Japan has collapsed after the Great Disaster. Kiruko accepts a request to take a boy named Maru to a place called Heaven. Meanwhile, children live behind the walls of a nursery in luscious green surroundings. After receiving a mysterious message, Tokio begins to doubt the world around him.

Mimihime, Shiro, Anzu and Taka all head outside through a hole in the wall, as they search for an answer to their teacher's test. Meanwhile, Kiruko is in tears after Robin does something terrible.