Hotaru, a model student attending a school in Tokyo, is a serious student with a strong sense of justice. She serves on the disciplinary committee and plans to attend a prestigious university after graduation. One day, she warns Kawagoe, a delinquent student, for bullying her classmate Meguro, and saves Meguro. However, Hotaru is knocked unconscious by Kawagoe's violence, fueled by anger at her actions, and is confined to a classroom with no students during winter break. And then, her well-fleshed model student body is endlessly devoured by vulgar people…