she is a girl who is known to be the girl that Futagami had a crush on. a while after her classmates were talking about futagami's doppleganger, she started to talk to him and searched for the ID of him.
she is an ID slayer which has a job to kill the ID that has "fallen to negative", because when she was a little girl, her brother was killed by his own ID that has "fallen to negative". when she was fighting a woman ID that grabs her hips and made her unable to move, she trusted Futagami to do what he can do to save her. she is save, with her breasts touched by the ID of Futagami that he moved his life energy into. at last she "force" Futagami to work with her to kill all of the ID's that is still out there.