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.

Maru and Kiruko find what they believe is the doctor and the Immortal Order. Instead, it is a hostile organization that is strongly opposed to the treatment that the Immortal Order provides.

After killing the Man-Eaters, Maru and Kiruko finally meet Dr. Usami. He asks something difficult of them, and leads them both to a room where a horrifying scene awaits.