The white room. A hellhole that takes in children and churns out perfections of the human society. Ayanokoji is the perfect human specimen, but he's one of two of them. Another girl is also deemed perfect at the same time, another survivor of the demonic fourth generation, a girl with long brown hair and dull yellow eyes, Ayanokoji's twin sister. Unbeknownst to him, she also joined the ANHS, and was put into class A. What sort of chaos will happen in this school, with two perfections there? Will they be freed from the prison of their hearts? Will the things they lost ever come back? Nobody knows. The number one thing on their list is to enjoy their freedom, so for now, that's enough.