Good children can go to heaven. Bad children can go anywhere. Before she knew it, the girl was imprisoned in an unfamiliar place. Her name is Yuzaki Eri. A Japanese born in the Heisei era. Just yesterday, she was attending high school like any other student. However, she has no memory of the moments leading up to this. In this world where anything goes—rape, theft, murder... she becomes intertwined with a "weapon". The highly anticipated female prisoner prison survival begins!