Ryuuko Matoi

She transfers into Honnouji Academy as a second-year student, an Academy ruled by power and authority. She wields a huge single-bladed scissor, and demands to know the owner of the other half. As she remembers, the wielder of the lost half of the scissor blade is the same person who killed her father.

Her body has been fused with life fibers, making her a "life fiber monster"
She is the daughter of Kiryuuin Ragyou, making Kiryuuin Satsuki her older sister