Chouma is a member of Septimal Moon and claims to be Kio Kaidou's sister. There is not much known about her. Nagisa Sagan said that Chouma needs a wheelchair; however, she is seen walking properly without one. She visits Kio while he is being kidnapped by Bloodless. It is believed by Nagisa and Nana that Seimei Aoyagi appearing at Seven Voices Academy was a diversion and that information, and possibly Chouma, were what he had intended to gain from the school.