Renton Thurston (husband)
- For the series, see Eureka Seven.
Eureka Thurston (エウレカ) is the main female protagonist; a member of the Gekkostate. She is the pilot of the Nirvash type ZERO, and sits along side her co-pilot Renton Thurston, with whom she falls in love and later marries. She is also a Coralian created by the Scub Coral and was meant to gather information on the human population. She starts off in the story as an aloof and emotionless young girl but grows up into a kind, caring, and almost entirely human-like woman. In Eureka Seven: AO, she is the mother of Ao and Amber.
Eureka is a girl born by the Scub Coral, a race of assimilating, intelligent lifeforms that landed on Earth via falling satellite (which was also named "EUREKA"), and is therefore a human-form Coralian. She is the pilot of the Nirvash type ZERO LFO. Eureka treats the type ZERO not as a machine, but as a companion with thoughts and feelings of its own. Initially, Eureka knew nothing about her origin or her true purpose before joining the Gekkostate due to her having no memories from before she was found by Adroc, who gave her the name "Eureka", taught her how to be an LFO pilot, and took on a surrogate father figure to her.
A bit of an enigma, Eureka is a young girl who has trouble communicating with and understanding other human beings. Eureka speaks very calmly and directly, and due to her initial lack of empathy, often comes across as blunt. She is often perplexed by other peoples' emotions and behaviors, making her naïve, especially when it comes to interpersonal relationships. She is considered to be one of the most excellent LFO pilots due to being the pilot of the TypeZERO, and used to be part of the United Federation's Special Operations Force unit until she left with Holland. Eureka ends up taking in three children orphaned during her time in the SOF, becoming their adoptive mother and learning a bit about humanity.
However, her physical and mental states undergo many major changes after meeting her partner and future husband, Renton Thurston, due to the strong feelings of love he harbors for her. Even though Eureka is blunt and emotionless, Renton takes an immediate interest in her, and his gentle, amusing, and determined personality becomes the thing that changes Eureka's character. Initially, she didn't return his feelings because she did not understand what they meant. However, as she gets to know him and sees just how much he is willing to do for her, she begins to fall in love with him and realizes she wants to be together with him forever. She eventually marries Renton shortly after Eureka Seven, and is listed as "Eureka Thurston", along with Maurice, Linck, and Maeter, as part of the Thurston family on the Residency Identification paper that Axel carries around.
In the beginning of the series, Eureka acts extremely distant and odd around others due to the fact that she has had very little interaction with humans outside the military. Because of her lack of emotions and care towards others, she was very blunt and serious, nonchalantly going along with anything that Holland suggested or told her to do without as much as questioning his judgment. However, things changed when she met Renton. Eureka saw something different in him as a person when she discovered that he is also able to pilot the Nirvash alongside her. As time goes by, she begins to act less a socially awkward girl and more like an actual person as parts of her human side begin to emerge.
However, she becomes passive and weary due to her feelings that Renton can pilot the Nirvash better than her, causing her to feel unwanted and hopeless. This also caused her to reject and ignore Renton, never realizing that she was simply jealous of him and lonely that her partnership with Nirvash was strained. After he saved her from getting absorbed by the Scub Coral, she slowly changed from uncaring to sympathetic as she started to understand the hardships Renton has endured for her sake. When she found out that Renton left, she bursts into tears and blames herself for his abandonment, and realizes how important Renton is to her. When they are able to meet once more, Eureka claims that she has "chosen" him as her lifetime partner. Despite being happy with Renton, she feels remorse for dragging him into a war and staining his hands with blood, and develops a strong desire to make him happy with her.
Through her relationship with Renton, Eureka opts for a change in her personality in order to become a better person. Although initially reluctant to accept the change in her in the beginning, she decides it is best for her if she truly wants to atone for her past misdeeds and comes to believe in Renton with her entire being. In season 3, when she is able to connect feelings of guilt to her worst memories, she becomes less confident and depressed, although she says that all she needs to move forward is having Renton by her side. It is his emotional support that allows her to try her best, no matter how bad the odds are against them.
In AO, she has became a lot more human-like and is always seen smiling. Eureka is more kind, helpful, and no longer naive, but she is still shy about her relationship with Renton, seen when Elena mentioned the moon with the heart on it from Eureka's world and when Ao asks about who the father is of her unborn daughter, Amber. After becoming a mother, she is very loving and caring towards her son and daughter, so much so that she is willing to put her son's life before hers.
She is constantly concerned about Ao's well-being and hides her sadness that stems from Amber's death so that Ao wouldn't worry. Eureka is very protective of Ao; seen in the manga when she challenged Truth while she was still in holographic form and was enraged at Truth for trying to kill her son, and in the anime when she pleaded with Ao and later Naru to destroy the Scubs or else Ao will suffer a tragic fate. Because her son and daughter are the most important people, next to Renton, in her life, she was willing to sacrifice everything else that was important to her, including her relationship with Renton. However, she always believed that Renton would come back for her and Ao, and that he was risking so much to protect them while she stayed behind to raise their son and attempted to risk her life for his, proving herself as a loving wife and mother.
About fourteen years before the series began, Eureka was found in a mine along with the Nirvash type ZERO's archetype and she was immediately brought to Tresor Laboratories for study. It was found that while the type ZERO would not work well with any human at the controls, it responded well to Eureka being the pilot. Soon afterwards, she met Adroc Thurston, who taught her how to walk, speak and interact with others. His influence on Eureka was that of a father. After Adroc's disappearance in the New Era Summer of Love, the then Lieutenant-Colonel Dewey Novak had Eureka placed under the care of his younger brother, Holland, who trained her to be an obedient child soldier. They were both assigned to the then SOF so that the military could use Eureka and the Nirvash for their benefit. During this time, Eureka grew to trust Holland to a degree equivalent to her trust of Nirvash, but she was still emotionally detached and unaware of her sense of self. Then one day, the SOF was given a mission to eliminate all the people living at Ciudades del Cielo under the pretense that they were terrorists for protecting the Coralians, and Eureka agreed to participate only because she believed in Holland. She killed many people until she found three small children traumatized but still alive in the pile of corpses she had just killed. Awakening to her senses of self for the first time and realizing that she had killed people, she decides to protect them. Taking them to the Nirvash, she rendezvous with Holland who was talking to Master Norb of the Vodarac. Later, she joins him in a revolt against the United Federation, aiding in stealing the Gekko, an experimental ship, and has been on the run ever since. She became an adoptive mother to the children and a respected member of the Gekkostate, but she never showed any emotion nor did she associate herself with anyone other than Holland and the children.
Three years later, she met Renton after she had been ordered by Holland to travel to Bellforest in the Nirvash to retrieve the Amita Drive under the guise of having Nirvash repaired. She crashed into the Thurston garage and Renton falls in love with her at first sight. The next morning, while talking to him as he repairs the Nirvash, she reveals that she doesn't need a Compac Drive to operate the Nirvash as others do. Renton decides to lend her his Compac Dive and inserts it into its place, saying that he's a professional mechanic who knows that machines have feelings too. Eureka surprises him by saying that that was common sense. She then uses the flamethrower on the remains of his room, which she accidentally destroyed in the crash, in order to give it a funeral, much to his dismay. She smiles upon seeing him having his shoes burned trying to put the fire out and then mourning them. On the Nirvash, the Compac Drive doesn't work so she tells him to take it off since she never needed it before and cannot believe in what she doesn't understand. She goes on to say that just believing in something doesn't mean something will necessarily come of it, sometimes belief leads to great misfortune and it can be hard to believe in anything at all. Renton tries to argue against this but Axel interrupts by voicing his realizations that Eureka is one of Holland's friends. He then produces a strange device saying that he knows that "this is what Eureka is after." He goes on to tell her that his family was torn to pieces because of this thing, so she can take it but never return. Suddenly, she senses missiles flying towards them and pilots the Nirvash out of its restrains and away from the garage before its destroyed. She then engages the oncoming KLFs in combat.
Holland and Matthieu try to join her in combat, but they are kept apart, and Eureka tries to lose the KLFs to no avail until the battle is interrupted by Renton's arrival on his ref board to deliver the Amita Drive. She saves him from being killed and finds him clinging to her, and he confesses his love to her. She doesn't understand what love means and is confused over his confession. He pulls out the Amita Drive, explains it to her, and then inserts it in. The result is that Nirvash deactivates and Eureka falls unconscious for a few moments. He is unable to pilot the Nirvash because it won't respond to him and she regains consciousness just enough to put her arms around him and tell him that he can believe in her. Suddenly the Amita Drive activates and the Seventh Swell effect is activated. The KLFs are defeated and Renton falls unconscious. Holland comes to retrieve Eureka and Nirvash, and then he comments of the power of the Amita Drive. Eureka tells him that the source of the power was Renton, and takes him back to the garage. Upon seeing Renton smile in his sleep, Eureka asks Axel why Renton is smiling and voices her opinion that he was being reckless. Axel tells her that Renton may have been reckless but he will still complement Renton because he is "family". Eureka doesn't understand what he meant and Axel tells her that she will understand when she becomes a mother. Eureka starts to say something but is interrupted by Holland, and she witnesses an argument between them. After talking to him, Holland invites Renton to join him and Eureka on the Gekko. Remembering his actions from earlier, Eureka asks Renton to come with them because she may need him, and he agrees. Holland notices Eureka holding hands with Renton and she says they need to get back on the ship. Holland objects and tells them that he will read the waves in case they need to make a forced exit, but she says she will do it. Holland curiously asks why because she wasn't feeling well earlier, and she says she feels a lot better, much to his surprise. Eureka takes Renton and shows him how to feel the waves, and says that he reminds her of someone she knew well. After saying goodbye to his grandfather, Renton leaves with Eureka and Holland. She comments to Renton that she has never felt the Nirvash as happy as it is now, and once aboard the Gekko, she introduces him to her adopted children.
Initially, her time with Renton was a difficult transition, due to the fact that she didn't understand his feelings of love towards her, and as a result, she didn't reciprocate his feelings. However, his presence on the Gekkostate causes a tremendous development on her physical and mental state, to the point where she gradually began to understand human nature and emotions. While she referred to Renton as a child and found him amusing, she tells him that she finds him interesting and truly enjoyed his companionship. When he is assigned to co-pilot the Nirvash with her, they form a special link together, which they later learn is necessary to activate the Amita Drive, awaking the Nirvash, and accessing the full power of the Seven Swell Phenomenon. In order to access the Amita Drive, Eureka and Renton must have an emotional agreement and an equal wish for something. If their feelings are disconnected, the Amita Drive cannot activate, even though there have been occasions where Eureka is present yet unconscious and Renton alone is able to awaken the Nirvash. During a brief stop at Ciudades del Cielo, Eureka becomes worried when she sees Renton leave after being assaulted by Holland and goes searching for him. She is attacked by members of the Vodarac who called her a "monster" and a "murderer". She then confesses to Renton her role in the massacre and that the Gekkostate's mission is to atone for their sins and stop the military. She also tells him that she needs him to help her pilot Nirvash because she, remorseful of what she did, wants to atone for her sins and Renton is the only other person besides her who can fly Nirvash. Pressured by Renton to confront her problem rather than hide them, she and him use the Nirvash to stop the military from bombing the city. He tells her that she truly made an atonement and she is the same person she was before, but Eureka cries for the first time in her life and says she may have changed from the moment she met him. The more she spends time with Renton, the more she started to develop human emotions and started to smile and laugh more frequently, and unknowingly developed a need to have him by her side. However, this change in her slowly began to scare her to the point where she questioned if it was alright to change because she knows no other way of living or interacting with others. She also wondered if the change was more or less benefiting or hurting her partnership with Nirvash as it began to respond more to Renton than her.
The initial primary antagonist early in the series was Anemone, who first attacked them when the Gekkostate investigated an Ariel Coralian. while battling Anemone, she had a strange "dream" with Eureka and Renton, with Eureka trying to find Renton, who eventually met with and was ambushed by Anemone. Eureka saves him from being killed, but suffers a physical and mental pain with Anemone. While trying to tend to her, Renton's wish to protect her activates the Nirvash and he is able to pilot it back to the Gekko. Several days later, Renton met with Eureka and Anemone within a house in a dream/hallucination. In the form of Nirvash, he defends Eureka from Anemone. After coming into proximity of a mine filled with Scub Coral and archetypes, Eureka's mental state declines and she seemed to suffer from an unexplained depression, which causes her to distant herself from others and reject their efforts to help her. Around this time, Eureka began to question her status as Nirvash's pilot, believing it has come to favor Renton more than her and was troubled that it no longer talked to her. This causes her to become jealous of Renton and she distances herself from him, even rejecting his attempts to understand what is bothering her. She eventually admits her helplessness and offers to let Renton be Nirvash's new pilot. Already depressed due to feeling betrayed by everyone, Renton rejects her. This and other emotional problems unrelated to Renton eventually lead her to conclude that everyone hates her and she removes the Amita Drive from the Compac Drive, which causes her to be sent into the depth of the mine and nearly be absorbed by the Scub Coral, but Renton is able to save her by subconsciously activating a Seven Swell and she is left encased in scub. A Vodarac priest is brought on the Gekko to heal Eureka, even though she loses most of her hair and receives scars from nearly being absorbed. While she recovers, Renton tries to make up with her and profess his love to her, but this scares her and she rejects him. This incident, along with the apparent fact that none of the crew members are concerned about his troubles, Renton decides to leave the Gekko. Once they discover him gone, everyone conspires to make sure Eureka doesn't find out, especially since she seems to have developed an interest in him (evident when she immediately started asking questions about love and why Renton hasn't visited with her). She has a heart-to-heart talk with Gidget and admits that she is confused about her feelings for Renton but wants to tell him so many things she is afraid to say, which leads Gidget to tell her that she is in love with Renton. Eureka becomes more interested in this and continues asking everyone where Renton is, but they lie to her about him being gone. However, the ruse doesn't last long, and upon finding out about his departure, Eureka is saddened and blames herself because she was mean to him, and discovers a desire to see Renton again. She then takes over the chores he had been assigned to do because "he isn't there" and wears his tracksuit in mourning. The pain of being separated from Renton nearly overwhelms her to the point where she tries to pilot Nirvash and go look for him, and breaks down crying when it doesn't respond to her pleas. Confronted with the fact that Nirvash needs both Eureka and Renton to function and seeing Eureka depressed as she missed Renton, Holland promises to bring him back for her sake. When he returns empty-handed and decides that their main priority is to change routes because of the anticipated attack from Charles and Ray, Eureka is enraged and asks why he has not found Renton. She correctly accuses him of hating Renton and deliberately leaving him behind. When he says she is more important than Renton, she rejects this and, no longer trusting Holland, leaves the ship to go look for him herself, just as he was returning to the Gekko to warn them about the Beams. Instead, she finds herself in a dangerous situation against Charles and Ray, who try to kill her and attack the Gekko. Renton launches the Nirvash and rescues Eureka, and they finally open up to each other about their feelings. Eureka declares to Renton that he is truly her partner because she can't do anything without him and says she has wanted to talk to him for a long time, and he says the same thing. Since their previous way of fighting led to the deaths of people, Eureka and Renton decide to take a merciful method of combat by disarming the enemy units. Nirvash responds to their feelings by releasing an energy wave that disabled every machine in their path. They then start to talk about how the time they spent apart from each other made them realize that being together is what is most important.
As a result of leaving the ship and going into combat without permission, they were sent to the brig with the children, although it was Holland's way of protecting them. They were given bulletproof vests and a gun by Moondoggie as the Beams attacked the ship. Talho comes to release them and take them to safety just as Ray holds her at gunpoint. Ray then became enraged when she heard the children call Eureka "mama" and tried to kill her; her hatred for Eureka stems from that Ray became sterile from the effects of the Seven Swell, and because Eureka was piloting Nirvash when it released the Seven Swell, she blames Eureka for her inability to have a child. Renton, however, tries to reason with her and pleaded with her to stop. Charles dies from multiple gunshot wounds from Holland, and Ray detonated a bomb in his body. Ray escaped back to her ship, and while the Gekko waited for her to attack, Eureka tried to comfort Renton as he blamed himself for Charles' death and told him how she hasn't been the same since she stopped hearing Nirvash. Renton told her the same thing, and Eureka is amazed of how much he is just like her. Ray then tried to destroy the Gekko again in a murder-suicide kamikaze attack before she dies herself. Confused over the events, Renton blames himself for the Beams' deaths and expresses his anger at everyone over how they treated him. Now understanding the hardships Renton dealt with for her sake, Eureka comforts him, saying she believes in him, and they decide to learn more about each other. Renton further demanded to know why Holland decided to kill them to protect him, and Eureka replied that due to her choosing Renton as her partner, Holland wants to protect them. They then decide to stay together after realizing they can't bear to be separated again. Although Eureka was happy with being with Renton, she understood that he still didn't want to rejoin the Gekkostate and his return was to reach a reconciliation with her. She wanted him to stay on the ship so they can stay together and was worried about being separated from him again. To repay the crew members for protecting them, Eureka and Renton cooked and cleaned the entire ship, but Talho ruined the moment by explaining the true nature of Eureka - she is a Coralian. Eureka admits to Renton that she didn't tell him sooner because she was afraid he would reject her, but he said he didn't care about it because she has been special to him since the day they first met. After this, Renton decides to rejoin the Gekkostate, much to Eureka's joy and relief.
Renton's continuing acceptance of everything about Eureka leads to a much stronger bond of trust, and Eureka comes to realize just how much Renton means to her, to the point where she acknowledges that she is falling in love with him and wants nothing more than to make him happy with her. During their brief visit to Tressor to have the Nirvash repaired and upgraded, Eureka and Renton watched a film about the origins of the Nirvash, and Renton learned how Eureka came to be Nirvash's pilot. Eureka tells Renton that she likes being with him because he makes her forget the terrible things she did but she broke down in tears because she feels guilty for dragging him into the war and staining his hands with blood. They attempted to share their first kiss, but were interrupted when Nirvash rejected the repairs. Eureka insisted to the scientists that the Nirvash didn't want to be repaired to its' original form and wanted to change, and she relates how she has changed into a better person. Based on the research from Dr. Bear, Eureka learns that the reason why she has no memories of her past prior to being found is because the Scub Coral deliberately created her with a clean slate so that she can experience human behavior and emotions, and forge her own human-like personality for the Scub Coral's benefit in understanding the humans. Prompted by Renton's reaction to the deaths of Charles and Ray, Eureka begins to understand feelings of guilt and regret, especially towards the massacre at Ciudades del Cielo. She knows that her past actions led to the deaths of many people, and because she is beginning to understand the human impact of killing and loss, she loses confidence in herself and no longer wished to fight with Nirvash. Renton helps her realize that they can only disarm enemy units and he constantly consoles her as she tries to deal with her past sins and take responsibility for them. When Dewey starts releasing the Antibodies to destroy cities and kill people to gain public support, Eureka was saddened and blamed herself because she knew it was own kind killing people, causing her to lose confidence in herself and lose the will to fight. Renton decided to cheer her up by asking her to ride Holland and Talho's longboard with him, and she asked him if she was a burden to him, which he denied and they happily rode the longboard in the middle of the sunset. Holland announced that he planned to disband the Gekkostate after completing their final mission, which was rescuing Norb from the military, but the crew decided to stay with him. Before going to the Capital, Holland spoke to Eureka and Renton because he decided to tell Renton about how me met Eureka and Norb. In a carefully planned mission, they invaded the Capital to rescue Norb from Dewey and the Federation army. Eureka reluctantly agreed to go along with it, but in midst of the mission, she forced the Nirvash into hiding and broke down to Renton that she didn't want to fight because she was afraid of killing more innocent people and wanted to run away from it all. Renton reacted by hugging her and assuring her that he will fight in her place due to his own desire to end the war between the humans and Scub Coral. This cheered Eureka up and they completed the mission by retrieving Norb from Dewey. However, after seeing Eureka and Renton pilot the Nirvash together and appearing to be happily in love with the other, he ordered Holland to get them to the Vodarac Shrine, where they could pass over the Great Wall and find a way to end the conflict between the Scub Coral and humans. Eureka becomes ashamed of her scars, and after learning how guys like girls who wear makeup from Gidget, she attempts to use makeup on herself for the first time to look pretty for Renton, but feels humiliated due to using too much of it and Renton tells her that he loves her no matter what she looks like. Overtime, Eureka learns more and more about human nature, specifically pregnancy and childbirth, which intrigues her. She later finds out that she can also conceive, carry a baby, and give birth like a normal human, which seems to strengthen her desire to have a family with Renton and the kids.
Days before their arrival at the Vodarac Shrine, Eureka and Renton talk about what might be behind the Great Wall, and Eureka replies it is the "future" and that his father, Adroc, once told her that. Renton was shocked that she knew his father, Adroc, before he died and that he was the one who taught her almost everything. This caused Renton to become upset and shout at Eureka for not telling him sooner, but she was confused due to her not understanding family issues and ran away. This caused a misunderstanding among the Gekko crew that Renton wanted to have sex with Eureka and she was resistant of him, due to Eureka crying about whether or not she deserved to be with Renton and due to Renton looking at adult magazines for relationship advice. Hilda and Gidget took Eureka aside to talk to her (it is implied they explained the facts of sex and pregnancy due to her immediately questioning about Talho being pregnant and how Holland was going to be a father), and she finally starts to understand the meaning of family. After reconciling with Renton, she later revealed that it was Adroc who released the Amita Drive during the Seven Swell event and his last thoughts were of his family before he disappeared. This revelation allowed Renton, who had thought Adroc abandoned his family for his research, to forgive his father, and Eureka thinks that how Adroc treated her was that of a father-figure. Shortly afterwards, Norb had the entire crew play soccer, and even though she had never played before, Eureka excelled in the game. She constantly cheered for Renton and even coldly told him to "stop joking around" when he made a mistake, but she later apologized and offered to cover his mistakes, much to his dismay. In the final round, she and Renton stepped on Holland's face to jointly score a goal. As punishment for stepping on Holland's face, they cleaned the hanger and Eureka told Renton that she said "I believe in you" to Renton during the game but he didn't hear her. She said to him that she feels that miracles seem to happen when he is around and that's why she can believe in him more than anyone.
The Gekko arrive at the Vodarac Shrine in order to get past the Great Wall, hoping to unite the humans and Scub Coral. At first, she refused to go and meet with the Vodarac because she doubted they would forgive her, but pressed by Talho, she agreed to go through with the mission. Initially, the crew planned to enter in disguise but an incident with the kids accidentally activating Nirvash caused them to hastily help Renton, Eureka, Norb, and the kids enter the Vodarac shrine. Led by Norb, they meet the first Coralian to be born from the Scub Coral, Sakuya. Sakuya tells Eureka her history, including how she fell in love with Norb and their failed attempt to pass through the Great Wall. She helps restore most of Eureka's superficial damage, but Eureka requests that her scars remain to remind her of what she's been through. Eureka related to Renton and Norb that Sakuya told her that she and Renton needed to be happy, and Norb encourages her and Renton to pass through the Great Wall and reach the genuine Promised Land. Soon afterwards, they are attacked by Anemone, and quickly entered the Promised Land in order to escape from her. They end up on a coastline and discover that they have landed on Earth, much to their shock. They are unable to find a way to return to the Gekko and failed to understand what their purpose on Earth was, which caused a temporary rift between Eureka and Renton, especially when she was unable to communicate with Nirvash. They wonder around the coastline for some time and come closer to the Scub Command Center. Eureka's scars begin to turn green and Coralian physical attributes begin showing throughout her body in reaction to the Scub Command Center. Thinking Renton will reject her changing form, Eureka hid them from him. When he does find out, she runs away but he catches up with her and even went as far as to damage his own arm to prove his acceptance of her changing form. This emotional moment caused Maurice to lash out at them; at Renton for "taking" Eureka away from him and ruining everything, and at Eureka for running away from her responsibility in taking care of them after killing their real families. Eureka calmed him down by asking him if he hated her smile and then assured him that she still loves him and his siblings now matter how much she's changed. Renton's wound got infected and he developed a high fever, and Eureka and the kids had to take care of him. During this time, she was sad because she felt she wasn't doing enough to help Renton and almost tells Maeter and Linck the truth about their real parents after Maeter has a small recollection of her mother but the kids insists that Eureka is their mother regardless. Then, she suddenly grew butterfly-like wings and her left arm became green and pink of Coralian design. After Renton recovered, Eureka was surprised but happy to hear him say he thought she looked beautiful with the wings, which prompted her to tell him that she loved him for the first time. From that moment, Renton and Eureka started contemplating their future, such as getting married, raising their adopted children, and having children of their own. Soon afterwards, Renton spotted his older sister and ran after her, which forced Eureka and the kids to chase after him and were lost in the great library created by Scub. They met with Adroc, who looked after them before Renton returned and she assured Renton that she would never leave him. When they exited the Scub Command Center, Anemone appeared and attacked them in order to destroy the command center. While fighting against her, they discovered her feelings of sadness and pain, and Eureka convinced Renton that they should try talking to her in order to help her understand her feelings for Dominic. After Anemone was saved by Dominic's arrival, all seemed at peace until Dewey fired his satellite cannon at the Command Center and destroyed it. Immediately afterwards, the Gekko arrived to rescue Eureka, Renton, and the kids, but Dewey's ship also arrived to fight the Gekko. After discussing what to do to ensure the Scub Coral won't wake up and activate the Limit of Questions, Eureka and Renton decide to take the Nirvash and the kids to become the new Command Cluster. Holland engaged in a gun battle against his brother in order to end Dewey's madness, but it all ended with Dewey committing suicide. However, the surprising move activated the collar-like devices Eureka and Anemone had always worn, which were designed to activate a self-destruct sequence that would destroy the Scub Coral if either girl would become the next Command Cluster. Eureka felt a sudden change in her body, and realizing her time with Renton was over, she apologized to him for their failed dream of being together forever, and transformed into a Coralian event.
Inside the Coralian event, as she was becoming the next Command Cluster, Eureka was in an artificially created plane, seemingly not on Earth due to the fact that it can be seen in the sky. She mentally told herself that she loves Renton and the kids more than anything and credits them for teaching her everything she now knows, but as much as she wants to save them by risking her life, she wants to see them again. Enraged at losing Eureka after having gone through so much with her, Renton decided to save her on his own. He begged Nirvash to awaken so it could help him get to her. It reacted by transforming into its apparent true form. With the Nirvash, Renton is able to easily destroy the Coralian antibodies, and his strong feelings for Eureka enabled him to break though the zone and reach her. Eureka was overjoyed that he really came to save her and he reminded her of his promise to always protect her. She tells him that she can never go back, but he tells her that she is making a choice to give being a Coralian in order to save the planet and he has chosen to give up being human because he treasures the planet he met her on. He gives her a flower hair clip and comments how beautiful she is. He then asks her to merge with the Scub Coral with him, which she agrees without hesitation, and they kissed for the first time. With the power of their true love, Nirvash is able to activate the Seven Swell Phenomenon, becoming the Second Summer of Love, and the couple's names are carved into the moon. Nirvash is able to push open the Coralian zone, and in a feminine voice, tells them that the Scub Coral has achieved enlightenment and half of the Scubs will be departing to another universe in order to prevent the Limit of Questions from happening again. It also tells them to set an example to the humans by living together and bring forth a new evolution (human-Coralian hybrid children) before Nirvash disappears. Eureka and Renton are relieved that they can now live a normal life together, and after agreeing to return to Bellforest, they kiss a second time before returning to the planet. A year later, the family record book lists her as Renton's wife and the kids as their adoptive children, confirming that she and Renton got married. As the children and Axel eagerly await their return, Eureka and Renton are seen together near a lake, holding hands and their foreheads glowing (hers blue and his red) to symbolize their deep connection.
Eureka Seven: AO Edit
Several years after the end of Eureka Seven, Eureka and Renton have two children; a girl and a boy. During her pregnancy with their daughter, Eureka and Renton were warned that high levels of trapar concentrations would affect their child and potentially result in death. Despite their concern, they chose to carry the pregnancy to term rather than choose an abortion. When Eureka was six months pregnant, they discovered that the Scub Coral was mysteriously disappearing, and began using the Gekko as part of an experiment to figure out why the Coral was disappearing. However, during the experiment, the Coral suddenly burst, taking Eureka and the Gekko with it to the year 2025. She met her future son, Ao, whom she instantly bonded with and told him a little about her history, including her relationship with Renton and how she came from another world. After being attacked by the Japanese military and Truth, Ao helped send her back to her world, and then did she discover that Ao is actually her son. Three months later, Eureka gave birth to their daughter and named her Amber. However, they were devastated when Amber turned as hard as stone and died at three months of age. However, they knew that Ao would be born, and still wanting to have a child of their own, they carefully planned a way to raise him in a world with no trapar and Scub Coral, and shortly after, they conceived Ao. They decided to keep their son and to raise him in the world where Eureka first met him. When Eureka was seven months pregnant, Eureka and Renton traveled to the future of Ao's world but were attacked by the Secrets, and Renton sent Eureka into the pillar of light in order to save her and the baby while he stayed behind to stop the Secrets from following her. Eureka refused to separate from Renton, who insisted that it was the only way to save Ao and he didn't want her to kill her own kind. Arriving in the year 2012, Eureka fell from the sky above Iwato island. She was rescued by Naru's father and Dr. Toshio Fukai, and two months later, she gave birth to Ao. She was feared by the island's citizens for her being a foreigner and having strange hair, but Toshio took her in and hid her and Ao. During her time on Iwato, Eureka dyed her hair brown to avoid suspicion and backlash from other villagers who resented her presence on the island.
Eureka raised Ao during the first two-and-a-half years of his life, and was a loving mother to him. She had his name embedded in her bracelet that would later be used to help awaken the Nirvash, and told him that he was meant to be its next pilot. By the time Eureka Seven: AO started, Ao (at age 13) had not seen his mother in 10 years because she mysteriously disappeared after leaving to stop the last Scub Burst. However, he later learns from Gazelle's father that Eureka was handed over to the American Forces when he was 2 years old, and he was left in Toshio's care. Although Ao initially believed that his mother was taken against her will by the military, it turns out she went voluntarily because she learned that Scub Coral and Secrets had found their way into his world and set out to destroy them in order to protect Ao. Most of the time, Ao wondered why his mother endured so much hate from the villagers for his sake, and learned that it was because she believed in his father coming back for them and she was keeping a promise to Renton to protect their son.
Due to her strange appearance and arrival, many people involved in the military and in politics distrust her and see her as a threat due to her connection to the Scub Coral and Secrets. The Japanese military became interested in finding Eureka and using her for their benefit due to her ability as an IFO pilot. However, the Secret that she encountered moments before she disappeared, Truth, develops a deep hatred towards her and desires to get revenge on her, and that malice was passed on to Ao after finding out that the boy is her son. She is referenced by Truth as being the true "owner" of the Nirvash Mark I, and Elena Peoples mentions to Ao that she was brought from another timeline by Eureka and saw multiple visions during the time-skip, such as the Gekkostate, Bellforest and the Nirvash typeZERO.
It was revealed in episode 12 that Generation Bleu knew how Eureka came to the Eureka Seven: AO world: by way of a Scub Burst, where she unconsciously fell from the Nirvash while she was seven months pregnant with Ao. Knowing this fact, the space team (known as Team Harlequin) teased Ao as being an "alien". During this mission, Ao, became trapped on a chunk of Scub Coral threatening to crash into the earth. When the chunk began to break up, the Gekko was shown to have been inside. As the ship entered the atmosphere the Nirvash type ZERO climbed out of the Gekko and through non-verbal communication instructed Ao to ride the Gekko like a board to avoid burning up in the atmosphere. After landing in the ocean, the cockpit to the Nirvash typeZERO opened revealing Eureka, stunning the bewildered Ao.
This Eureka comes from a time before her first appearance on Earth, as she is still pregnant. In episode 13, she is revealed to be more human-like and no longer naïve like she was in the original series. However, she is shown to still be shy about her relationship with Renton, seen when she became embarrassed and blushed after Ao asked about the father of her unborn baby. She developed an instant bond with Ao, who asked her questions about her husband and past. Eureka reveals that she was part of the crew from the Gekko and her husband, Renton, was also a crew member; she became embarrassed when Ao asked questions about how she met Renton and described him as "immature, a crybaby, and a bit hopeless" but added that she loved everything about him. She also tells Ao that she and Renton were involved in research on the disappearance of the Scub Coral and she was brought to Ao's world by a Scub Burst, and how his Nirvash IFO is similar to the one Renton is designing. Once Generation Bleu arrived, Eureka was left with Rebekah and said that while she was worried about giving birth, she was more scared of her child hating her because her doctors warned her about having a human-Coralian hybrid child in a trapar-filled atmosphere. Truth and the Japanese military attacked in order to capture Eureka, but she and Ao fought back and escaped. Prior to the confrontation, Ao had encountered his mother, who was in her present self but in holographic form, and she asked him to return her to Renton before it's too late. She ended the conversation by telling Ao that the Secrets are not his enemy, which confused him. The Nirvash TypeZERO forced Eureka into midair while it fought Truth and she was saved by Ao, who then brought her to a pillar of light to return her to her world. Before separating, Eureka asked Ao why he called her "Mama", and he replied that he wished for her to give birth to a healthy son (he believed that he was the baby she was carrying) but Eureka surprised him when she revealed that she was carrying a girl before she disappeared into the light. This caused Ao to search family albums and journals for information about his older sister, and when he asked about whether or not his father abandoned him and his mother, Toshio recalled when he asked Eureka the same question; she was in the middle of giving birth to Ao when he asked her why her husband wasn't here and she replied that he was fighting to protect her and their son. In episode 14, also in holographic form, she appeared to Naru and asked her to help Ao destroy the Scub Coral before something terrible happens to him, but Naru ignored her.
In episode 17, she once again appears before Ao in holographic form, telling him about the events that occurred when she disappeared and that the Quartz Gun he possesses is the same weapon his father, Renton, has been searching for the whole time in order to save them. In episode 21, Eureka appears before Elena and Maggie Kwan as a hologram, trying to contact Ao. Ignoring her questions about Ao's whereabouts, Elena lunges angrily toward Eureka and pleads with Eureka to take her back to "the world with the heart on the moon", much to Eureka's embarrassment. Eureka understands Elena's anger and tells Elena that she is not from Eureka's world, but rather was saved by Eureka from a scub burst in 1981 and carried to a different point in Earth's timeline. She appears in holographic form one last time in episode 23, just as Renton arrives in the year 2025, and the two are briefly reunited. They are happy to see each other again but Eureka tells Renton to not touch her because he wouldn't be able to due to her being in holographic and she apologizes for her sacrifice. She tells Renton that Ao has grown into a good and energetic boy and is as honest as him, and has what he's been looking for before she disappears.
In the final episode, it was revealed that Eureka gave birth to her and Renton's daughter, Amber, three months after her return from Ao's world, but Amber died when she was 3-months-old due to the Human and Coralian cells rejecting each other due to the high level of trapar, which turned her body as hard as rock. As soon as Eureka became pregnant with Ao, she and Renton decided to search for a world with little to no trapar so they can raise him together, and chose Ao's world, which she discovered by accident the first time. While being attacked by Secrets, Renton sent Eureka to the year 2012 because it would be safe for their son to live in and they destroyed any Scub Coral that existed in Ao's world. Eureka's holographic appearance is explained to be due to her being trapped in a state of limbo between parallel universes caused by her using the Quartz without a specific destination in mind. saddned by the loss and sacrifices his parents have endured for his sake, Ao resolved to save his mother and reunite her with his father; he travels back to the point in time before Eureka disappeared with the Quartz and they reunite. Eureka admits that she knew Ao was her son because she learned the truth the moment he first sent her back to her world and she told Renton that they would have a son one day. When Renton arrives, Ao asks her to leave with Renton and return to their world. Ao further says he is to blame for them sacrificing so much by killing the Scub Coral in order to protect him, but Eureka insists that everything that has happened is her and Renton's responsibility for falling in love and having children. Although she refuses to part with her son, knowing she may never see him again, she goes with Renton, as Ao wants to repay his parents for sacrificing so much in order to keep him alive. After this, she possibly never sees her son ever again.
In the manga, Eureka was created by the Coralians with the mission to find the "chosen one" so they can "eat" him, enhance their evolution, and destroy the human population. Eureka was found by Adroc and quickly transferred to the military after his death, where she was partnered with Holland by Dewey. Like in the anime, Eureka took part in the Ciudades del Cielo massacre for no reason other than because Holland told her to go along with it, and she never understood what she had done until she found the three children crying and injured. Realizing she had killed people, Eureka decided to quit the military, took in the children, and joined with Holland to form the Gekkostate in order to stop Dewey and the military from destroying the planet. Unlike the anime, Eureka falls in love with Renton much earlier. Eureka took an instant interest in Renton after becoming intrigued by his shy yet good-hearted nature. However, while she failed to understand what the term "love" meant, everyone quickly noticed her growing feelings for him, and even Eureka questioned the change in her. While she enjoyed Renton's companionship and appreciated his help, especially when he saved her from the Coralian, their inability to communicate caused a strain between them. When Renton learns of his father's murder and the Gekksostate's war with the military, he asks her to leave him alone. Devastated, Eureka concludes that love is painful and decides to stop trusting people to stop the pain.
After Renton rejected her offer to pilot Nirvash in a fight against Anemone, leading her to nearly be killed, she is encased in scub by her choice to stop trusting. However, when some SOF soldiers were about to kill her and Renton risked his life to save her, Eureka was overcome with guilt for denying her love for Renton and joy to know how much Renton loves her. Together, they pilot Nirvash and release a Seven Swell to stop the ambush, allowing them to reconcile and enter in a relationship. However, Eureka is later controlled by the Coralian Zone into luring Renton to the Zone, but instead she is pulled into it with Anemone. It turns out that Anemone is not in fact her enemy, but a good friend. After realizing the Coralians' true intentions, Eureka rushes to save Renton from being eaten by a fake Eureka. He is nearly eaten and Eureka risks her life to reach him as they fight the Coralian. They reject the Coralian's theory of fighting and killing in order to survive, and insist that protecting the one they love is the true way to survive. They successfully destroy the Coralian Zone and share their first kiss. As they watch the Coralians disappear, Eureka begins to disappear and shares her final moment with Renton; she tells him how happy she is to have met him and embraces him before she fades away, leaving Renton heartbroken. Two years later, everyone, but Renton, has accepted that Eureka is dead because of the Coralians being destroyed. Renton, however, believes that Eureka will someday return to him because of her choice to live. As he looks up at the sky, he sees a rainbow and senses Eureka grabbing his hand as he reaches out to it.
In the film, Eureka is a spy robot created by the alien race, the Azos, in order to gather information on the humans so the Azo can destroy them. During her childhood, she was cared for by a scientist couple and became best friends with their son, Renton. She was also close to Professor Dominic as he taught the children about dreams coming true by believing in them. Due to her nature, Eureka is unable to live in sunlight, which can cause significant damage to her skin that may be fatal. After the professor's death, Eureka was taken away by the military and repeatedly experimented on, leading her to attempt suicide several times but never followed through with it due to her desire to reunite with Renton. Eight years later, Eureka is rescued by Renton as he was searching for the military's top secret project (Eureka). Even after Eureka explains what she really is to Renton and why the chance of them having a future together is slim, Renton vows to do whatever it takes for them to stay together. It turns out that Eureka is the "chosen girl" and Renton is the "chosen boy", and together, they can open the gates to Neverland, where dreams can come true. The Gekkostate sought out the two because they wish to remain eternally young. After seeing Renton get shot in order to save her and see the selfish lengths the Gekkostate will go to get to Neverland, Eureka threatened to kill Anemone if they didn't do anything to help Renton. Anemone tells Eureka that because they were created by the Azo, if they die so will the planet for becoming one with the Azo and Eureka needs to have a dream that comes true in order to save the planet. Eureka flees with Renton as they confess their love to each other and vow to form a future as a couple. The fight against Holland causes Renton to lose consciousness from blood loss and Eureka decides to sacrifice her memories to save him. Although she now knows how hateful the world is, she wants to save it because it is where she met Renton. As a result of her sacrifice, they are transported to Warsaw and Eureka is left naked with long hair and incapable of speech. Although she has lost her memories, Eureka's love for Renton clearly remains, evident when she kisses him on the cheek and they hold hands.
Eureka's Original FormEdit
Initially Eureka looks like a normal human being with the exception of her turquoise hair, which she often wears with golden hair clips, and eyes, which are a bright purple with stained red rings due to her Coralian origins. Her appearance in the entire series shows her having short hair until she lost most of it after nearly being absorbed into the Scub Coral (it was later restored back to its original length in season 4), and pale skin color. Her true age is unknown to due to that humanoid Coralians age slower than a normal human; from her discovery almost fifteen years before the story takes place and until the beginning of Eureka Seven: AO, she retained the appearance of a teenage girl; most on the Gekko assumed her age to be roughly between 14 and 16. After her marriage to Renton, it was decided that she was 16-years-old, the same age as him. In Eureka Seven, she always wore blue and white cut-off dresses.
Transformations in the mangaEdit
After being attacked by Anemone and the typeTheEND, Eureka underwent a transformation after she and the Nirvash suffered damage from TheEND. Hurting from Renton not being there for her, and feeling saddened by not being able to understand her own feelings towards him, Eureka decides not to try believing in love anymore. However, this mental decision effected her physically; her skin became covered with slime and huge scabs that hindered her movement. Her eyes also became disturbingly void of emoiton. In appearance, it appeared like she was in the center of a large bed of lettuce, or cabbage.
After watching Renton woundedEdit
When Renton was badly wounded protecting Eureka from the new SOF Squad sent to gather Eureka's Bio Data and eliminate her, Eureka's love for Renton came back and she tore off the scabs holding her. The result was that mentally, Eureka learned that love hurts but also can give joy; while physically, Eureka gained scars all over her body.
Transformations in the animeEdit
After being absorbed by the Scub CoralEdit
After Renton saved Eureka from the Scub Coral absorbing her, she is found to be covered in a thick scub-like substance from the Scub Coral which is fused with her skin. Mischa was unable to remove the substance without harming Eureka, so Holland decides to accept a mission to save a Vodarac High Priest. Once saved, the High Priest performs a Guidance Ritual to release her. Free of the scub, Eureka emerges with short light blue messy hair and lacking eyebrows; there are scars going along her left side because of how the Coral was absorbing her. She bears this form until meeting Sakuya in episode 41.
After meeting SakuyaEdit
Before leaving Sakuya's heart, Eureka is offered to have her scars fixed but she refuses saying that these scars are the outward proof of what she has been through. Sakuya responds by commending Eureka's strong will. Upon emerging Eureka is shown to have regained her former appearance. Her hair is now loose without the clips holding them back and her scars have become less prevalent.
After reaching the Promised LandEdit
Upon passing the Great Wall and reaching Earth, known as the Promised Land, Eureka undergoes her most intense transformation yet. As she begins to morph into her Coralian form, her left arm begins swelling and portions of it turn a light green. Afraid of what Renton and the children might think, she initially tries to hide her arm and distances herself from them. When they notice the transformation, she runs away. However, the others soon find her and her secret is revealed. Renton, concerned for Eureka and deeply hurt by her pain, violently and repeatedly bashes his left arm with a rock in a fit of anger so his arm will be different like Eureka's. Eureka, while shocked by Renton's actions, finally understands that Renton will never abandon her no matter what and reconciles with him. However. Renton's injury becomes infected and he develops a high fever as a result. While caring for a sick Renton, Eureka sheds a tear and her left arm completely morphs into Coralian form, furthermore wing-like appendages grow out of her back. Eureka is once more afraid of what Renton might think when he wakes up, but upon seeing her, Renton is entranced and comments on how beautiful Eureka has become, much to her joy.
Eureka's Final FormEdit
When Dewey dies, the collar on Eureka begins affecting Eureka's physiology and her skin morphs completely into Coralian green before she is enveloped in a sphere of black and red energy. When Renton and the Nirvash Spec3 force their way into the sphere, Renton encounters Eureka who has all but returned to her original appearance from the start of the series while retaining her Coralian wings and she no longer bears the scars on her body. Renton ties her hair back with a flower hair clip, revealing a small green gemlike spot in the middle of her forehead.
Eureka Seven: AOEditIn AO, now around age 30, Eureka has noticeably aged and grown taller, but is most recognized for her maturity and kindness. Her hair has become straighter and is at the same length as in the first series, and she still has the small green gemlike spot on her forehead. While living in the 21st century of an alternate universe with Ao for three years, she dyed her hair brown to avoid suspsicion. In episodes 12-14, the pregnant, past incarnation of Eureka that Ao encountered looks exactly the way she did before she disappeared after taking the Quartz away from Okinawa. She also wore a new blue and white dress in place of her old one, even the same one during both of her pregnancies. She still wears hair clips in her hair, especially the flower hair clip Renton gave to her. In Eureka Seven: AO, it is revealed that she can also summon her wings willfully.
Renton is Eureka's partner and husband. Renton and Eureka's relationship is the most complex throughout the story, starting out as a one-sided love on Renton's part due to Eureka not understanding human emotions, to co-pilots, to love interests, to husband and wife. When they first meet, Renton is speechless and entranced by her beauty and Eureka was confused by his advances. In Eureka Seven: AO, Eureka told their son, Ao, that she thought of Renton as immature, a crybaby, and a bit hopeless when they first met, but ended the comment by saying she loved everything about him.
Unlike how most of the Gekkostate treated her with respect as the pilot of the Nirvash, Renton instead sought to help her overcome her struggles as much as he could after she confided in him about her past misdeeds and desire to atone them, and he often told her that she can become a better person through the change in her. Overtime, as Renton begins to understand how his role affects Eureka and that of the Nirvash Type ZERO, he vows to protect her. Because of this, Renton's admiration and infatuation towards Eureka later grows into genuine care and affection, allowing him to truly fall in love with her.
However, Eureka was oblivious about what "love" meant and did not reciprocate his feelings. Despite this, she appreciated his companionship and admitted to him on more than one occasion that she found him to be the most interesting person she'd ever met. Originally the two of them were partnered to pilot the Nirvash, with Renton guarding the Amita Drive, but Eureka found herself intrigued by Renton's good nature and shyness. Eureka credits his presence on the Gekko for allowing everyone to have fun and be more open with one another. When Eureka goes through her depression over losing her partnership with Nirvash, she thought that Renton was somehow responsible for this due to him being to pilot it with more ease, and she became jealous and little bit angry at him.
However, she later reveals that she never held any negative opinions towards him and wanted to tell him about her confusing feelings for him. After learning of his abandonment, she bursts into tears, casted all the blame on herself, and became desperate to see him again. This leads her to realize that she had indeed fallen in love with Renton, and for the first time, she even lashed out at Holland after he said that Renton was not important. After the two reconcile, Eureka declares Renton as her partner and puts all her faith in Renton, and tells him that she can overcome anything as long as she is with him.
After entering in a relationship, she becomes very devoted to him and takes most things Renton says to heart, and looks to him for help. She becomes determined to make Renton happy with her, seen when she tried to use makeup for the first time to look pretty for him and when she assured him that she would never leave him after he asked her to stay with him forever. Her love for him has also grown so strong to the point where she can't bear being apart from him and she quickly envisions herself marrying him and having a family with him. It was because of Renton and Eureka's deep love for each other that allows them to perform many of the impossibles, like going to the Promised Land which is Earth, and saving the world from the Limit of Questions.
During their time on Earth, Eureka had doubts over how Renton would react to the changes on her body, but after he told her that she was still beautiful, Eureka was overcome with happiness and tells him that she loves him. Later, when Eureka was about to become the next Command Cluster, she apologized to Renton that she can't be with him afterall. However, Renton rescued her on his own, promising to be with her forever and they shared their first kiss, allowing them to activate the Second Summer of Love and save the planet. After Nirvash's departure, Renton and Eureka decided to return to Bellforest and raise the children together as a family. A year later, Eureka marries Renton and is listed in the family record book as "Eureka Thurston". Years later, in Eureka Seven: AO, Eureka is still married to Renton, and has a son and daughter with him.
Maurice, Maeter and LinckEdit
Maurice, Maeter, and Linck are Eureka's adopted children and, next to Renton, are her most beloved people. Orphaned during the SOF attack on Ciudades del Cielo, Eureka discovered the children crying beneath a pile of corpses. Horrified by what she had done, Eureka took them in and quit the SOF along with Holland. Eureka loves the children, but due her lack of knowledge of raising children, she often spoiled them and rarely, if ever, disciplined them until Renton teaches her what she needs to do to be a parent. The children tend to misunderstand the way Eureka expresses her feelings and often worry that it will mean she will abandon them. The children love Eureka very much, even referring to her as "Mama" and are very protective of her. Their protectiveness causes them to be very jealous and suspicious of Renton at first, as they believe he is "taking Mama away from them". However, later on in the series they warm up to him quite a bit and accept him as a part of their family.
Ever since Eureka was found, Axel Thurston was a part in building new technologies for the Nirvash type ZERO and he seems to be fond of her, to the point where he reminds Renton to bring Eureka when he decides to come home. Adroc Thurston was the one who taught Eureka how to speak and think, and served as a father figure to her until his mysterious disappearance during the First Summer of Love, which she later found out that he was with the Scub Coral. Despite that she lacked the emotions back then, Eureka recalled that her time with Adroc was a happy one and she liked his kindness. It seems as though Eureka did not know about Diane Thurston until she meets her in the Control Cluster. Despite being a Coralian, Eureka was welcomed into the family and accepted as Renton's wife. She becomes a member of the Thurston family after marrying Renton at the end of Eureka Seven, and gives birth to a daughter and son, Amber and Ao Thurston.
Ao is the son of Eureka's son. Out of all her children, Ao is her pride and joy, and she refers to him as "My Ao". While pregnant with her son, she was sent to the year 2012 by Renton in order to save her and the baby, and gave birth to Ao soon after. With only Toshio Fukai knowing her true identity, Eureka concealed herself from the other residents of the island by dying her turquoise hair brown. She raised Ao for the first three years of his life and taught him many things, especially the meaning of love, and believed that Ao will become the true pilot of the Mark I.
However, the residents of Iwato Jima handed her over to the American military ten years ago prior to the aftermath of the last Scub Burst to hit the island. By fate, getting flashbacks of his mother while he was little, Ao was able to become the pilot of the IFO Nirvash Neo and his brown hair turned turquoise like hers in the process. It was revealed in a flashback that Eureka loved her son deeply and was sad to leave him behind. She appeared to him in holographic form several times to warn him of his fate if the Scub Coral continued to exist, and was heartbroken when she returned with Renton to their world without Ao.
Amber is the daughter of Eureka and Renton. While pregnant with her daughter, Eureka showed great affection and devotion towards her baby, but was also worried about giving birth due to being warned about Amber possibly being affected by high levels of trapar and if Amber would hate her for her decision to give her life despite the risks. Along with Renton, she was devastated over Amber's death, and rarely spoke of her, possibly out of guilt that she may be responsible for the circumstances surrounding Amber's death - that she was aware of the risks of having a hybrid child in a trapar-filled atmosphere but still chose to give birth because she longed to bear the child of the person she loved the most. The loss of her daughter motivates Eureka to travel to an alternate universe in order to give birth to and raise Ao, and to destroy the Scub Coral, which she blames for depriving her of both of her children.
Eureka joined Holland's SOF squad shortly after Adroc's disappearance and the military sought to use Eureka and the Nirvash for their own benefit. She was placed Holland's care after he saw that she was the perfect pilot for the Nirvash. Before meeting Renton, Eureka trusted Holland more than anyone and did whatever he told her to do without questioning the legit of his judgment. Holland always thought as being the partner of Eureka, but Norb states that Eureka will have a partner other than Holland due to him treating her as a weapon.
Her partner ends up being Renton, who initially is the only one to make her truly smile from the heart. Still, Holland protects Eureka from harm and does not accept that Renton is her partner, often abusing him and later justifying it as part of his protection for Eureka. Eureka was aware of how badly Holland treated Renton, but her loyalty and dependence on Holland prevented her from doing anything to stop the treatment. However, after Holland told her that Renton was unimportant, Eureka was angry at him and temporarily lost her trust in him. Once he was able to accept the relationship and go at great lengths to protect the couple, Eureka regained her trust in Holland, and while she doesn't condone him for his actions, she understands that he wants to make amends and learns that she doesn't need to rely on him for everything.
Eureka has a special status aboard the Gekkostate as a skilled LFO pilot and is one of the organization's original members. Many members of the Gekkostate like and respect Eureka and are protective of her, though perhaps not to the degree of Holland, the children and Renton. She is well-liked by her crew mates for her partnership with Holland and later Renton, and for her role as an adoptive mother to the children.
Initially, Eureka rarely associated with the crew, preferring the company of Holland and the children prior to Renton arriving, and the crew was hesitant to speak to her due to her tendency to be blunt. However, she later develops a good relationship with all of the crew, particularly Gidget who helps her strengthen her relationship with Renton, and later Talho Yūki, who becomes a surrogate mother-figure to her.
Eureka and Anemone were sworn enemies for the majority of the series. Anemone developed a homicidal rage towards Eureka and the Nirvash, whom she deemed as a powerful threat to her and TheEND. Eureka didn't know about Anemone's existence until she and Renton first fought her in episode 13, and didn't know Anemone was an artificial Coralian until the fourth season.
Despite Anemone's ruthlessness, it is not part of her true character but the result of the mood drugs Dewey subjects her to when she is sent into combat. Eureka later learns Anemone is actually damaged physically and mentally, and really wants to live a normal life with the person she loves. She, along with Renton and the kids, try to convince Anemone to accept her feelings for Dominic in their final battle. After this, the two seem to be on good terms and Anemone admits she is jealous at Eureka for having so many people who will risk their lives for her.
After Toshio and Mitsuo Arata save Eureka's life after she fell from the sky, Toshio takes her in, along with her unborn son, Ao. Upon learning her history, he was willing to protect her from the islands residents who felt that she brought misfortune upon them. In retaliation, the residents vandalized his medical clinic by breaking glass and spray painted the walls, and yet he still protected her.
He willingly adopted her son, Ao, after Eureka disappeared during the Scub Burst 10 years ago after the Allied Forces took her away to deal with it, treating him like his own grandson and giving the boy his surname to protect him from the residents. The last thing Eureka told him before she left was for him to take care of Ao for her and she needed to leave her son behind because Renton wouldn't be able to find them and everyone will die from the Secrets.
- (To Renton) If you don't believe in anything, it no longer has the power to hurt.
- (About self) This is me, a book without words.
- (To Renton) You see...I was a military dog.
- (To Renton) Let's go together, because it doesn't work without you.
- (To self) What is love?
- (To Renton) Let's go back together.
- (About Renton) Oh, Renton...I want to see you.
- (To Renton) It's all right. You see, I believe in you, Renton. I believe in you with all my heart, no matter what happens, so please, Renton, talk to me about everything. I want to know all there is to know about you.
- (To Renton) I love you so much, Renton!
- (To Renton) If I'm with you, I can do anything.
- (To self) I have people dear to me. Linck, Maeter, Maurice, and Renton. I like them a lot. I love them. People dear to me, my family. They taught me all sorts of things when I didn't really know anything. They accepted everything about me before even I did. They let me be who I am. I want to be with those that I love, that I want to protect. I want to be with Linck, I want to be with Maeter, I want to be with Maurice, and, of course, Renton. But if wishing so causes those that are dear to be to be lost, if wishing so makes the planet where they all live disappear, then I will stop wishing. But if it can be allowed, I would like to see them one more time. I want to see you. I want to see you...Renton.
- Eureka's true age is unknown and some of the Gekko crew thought of her as between 14 and 16. It is revealed that Eureka was found the same year Renton was born. After becoming Renton's wife and the mother of Ao and Amber, she has noticeably aged.
- In the anime, Eureka was ashamed of her scars because they made her feel she was unattractive to Renton, while in the manga, she was grateful of her scars because she got them as she tried to prove that she loved Renton.
- In the film, Eureka Seven: Pocketful of Rainbows, Eureka's last name is Zita.
- After marrying Renton in episode 50, she goes by the name Eureka Thurston.
- In episode 50, the Thurston family record book revealed that Eureka married Renton on April 2, 12006.
- In episode 19, Eureka attempted suicide by almost allowing the Scub Coral to absorb her. This is due to her depression as being estranged from Nirvash and her belief that she is hated, and when she found a book with blank pages, she compared herself to it and felt she had no purpose in life. However, the thought of dying scared her and she pleaded for Renton to save her, which he did.
- In episode 39, Eureka is shown to be skilled in playing soccer, despite having never played before, and her jersey number was 7.
- In Eureka Seven: AO, her attire is similar to the one her sister-in-law, Diane, wears in the original series.
- In Eureka Seven: AO, her son, Ao, inherited his eye and skin color from her while having inherited his facial features from Renton. Early in the series, his hair was brown like Renton's but it changed into turquoise when he first came into contact with the Nirvash IFO.
- Eureka stated in both Eureka Seven and Eureka Seven: AO that what she loved most of all were Renton and their children (2 biological and 3 adopted).
- Even though Eureka has five children, it appears that Ao is her favorite, likely due to him resembling Renton and being the only one of her two biological children to survive, and she affectionately refers to him as "my Ao".
- Eureka is named after a famous exclamation attributed to the Greek sage Archimedes.
- Even though she calls Maurice, Maeter, and Linck her children and loves them dearly, Eureka never mentions them in AO.
- In the manga and novel series, Eureka sacrifices herself to save the planet from being destroyed (by the Coralians in the manga; by Dewey in the novels), and although he refuses to accept Eureka's death, Renton treasures her memory. In the anime series, she was supposed to sacrifice her memories in order to save the planet and part ways with Renton, however, due to the popular ratings, the ending was changed into a happy one where Eureka and Renton would be able to live happily together. In 2010, the producers of the series released an audio of the original ending with recurring scenes from the series, where of which Eureka parts ways with Renton forever after sacrificing her memories and disappearing, but he promises her they will meet again someday.
- The only time Eureka ever turns into a full human is in the film, after which she sacrifices her memories to the Azo to save Renton from dying due to a gunshot wound.
- How Eureka sacrificed herself in Eureka Seven: AO to teleport the Quartz to a different time in order to save Ao and the planet from a Scub Burst is similar to how her father-in-law, Adroc, sacrificed himself in Eureka Seven by removing the Compac Drive from Nirvash in order to save his children and the planet from the First Summer of Love. Also, many believed the two had died as a result of their sacrifices, but in truth, Eureka is in limbo between worlds due to not having a specific time and place in mind, and Adroc merged with the Scub Corals for an unknown reason.
- In chapter 2 of the second light novel, Eureka actually told Renton that she hated him for flying Nirvash in a manner that opposed hers. This is only time she has ever said this to him in the entire series. In the anime and manga versions, while she was jealous of him, she said she never harbored any ill will towards him and would worry that anything hurtful she said or did to him would make her lose him.