Shishidou Hiyo is a girl who was initially depicted as being madly in love with Sora after being rescued by her though this turned out to be an act. Hiyo has an older sister who always fought against the male dominance, resulting in injuries that forced her to drop out of school. Reiko mentions Sora was a lot like Hiyo's sister, because she was reckless and had similar ideals though this earns Sora Hiyo's contempt at her success. Eventually the gang finds out Hiyo stole the record of all the saved girls, ordering Tougyu to attack them. It later turns out she was manipulated by him to avoid the same fate as her sister. After Tougyu incapacitates himself, she becomes Sora's weapon. She is one of the six "stars", and her weapon is a large axe.