『Nonoka Mamiya』

She is Akari's younger sister and a middle school Student and one of the few non-antagonistic characters who do not attend Butei High School. Unlike Akari, Nonoka is mature for her age; she does the housework and wakes Akari up every morning. Like Akari, she is also the object of Shino Sasaki's crush. Two years before the events of the story, her family's estate was attacked and destroyed by IU and she herself was poisoned by Kyouchikytou which would cause her to slowly lose her eyesight. Her condition worsens during the events of the story but she is eventually cured by Akari who defeats Kyouchikytou with Aria's help.