Miller is a singer employed at Generation Bleu, where she and two other members of her band perform.
Miller is a dark-skinned girl who has purple hair, and has a slim physique, and many find her very pretty, such as Pippo who called her "very sexy." She wears typical indie rock/goth apparel, such as a purple color scheme, lipstick, and a choker, as well as piercings and fishnets.
Little to nothing is known about Miller's history before her employment at Generation Bleu, although she had performed Manchester prior to joining.Miller is first seen during Truth's attack on Generation Bleu's headquarters. She is one of the only people left alive after Truth attacks the area she is performing in. After briefly conversing with her, Truth knocks her unconscious.
Miller is later the topic of investigation under Gazelle, Pippo, and Han Juno, under the President's orders. She is suspected to be a spy for the Americans based on her communication records by the President and Gazelle. Later, Gazelle suspects that Miller is in fact a disguised Elena Peoples, which is further implied by a 97% appearance match with Elena, which Gazelle notes cannot be coincidence. Despite this, a DNA test shows that Elena and Miller are not the same person, further shrouding the situation.
Elena later dresses as Miller while in her room, before having a vision of Eureka and asking an apparation of Miller who she really is, before she starts to hallucinate due to Secret in the form of sand/trapar, who had sneaked through the Headquarters undetected, exciting her brain functions. Miller later is confronted by Elena during another hallucination, and Elena starts to act as though she is Miller and questions her self-identity. Elena buries the wig she used when dressing as Miller in the dirt, and says farewell before returning to her normal personality, further implying that Miller is a split personality of Elena.
When pronounced in a Japanese manner, "Miller" is a homophone for "mirror".