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 return to Tokyo to find a neighborhood crowded with tents. When Maru goes off to a game center, Kiruko is left to gather information for herself, and hears a scary rumor.