Midway through summer vacation, 36 students, some with newfound super-powers, find themselves all alone in their high school, adrift in a black void, unable to contact the outside world. Some students try to impose order, but are faced with opposition.

The students have relocated to a nearby island, where they have no shortage of food, and can get whatever they want through Mizuho's power. Suddenly, unexplained fires begin breaking out, and the hunt is on to find out who or what is causing them.

While traveling the wilderness, Mizuho asks Yamabiko how he became a dog. Yamabiko then relates how, 5000 years ago, he wandered different worlds all alone, until meeting a girl to whom he gradually opened his heart. But their happiness was short-lived.

After learning of Nozomi's death from Kossetsu's letter, Nagara and Mizuho hold a memorial service for her. While advancing the project to return home, they are visited by an old friend, who tells them the story of when he met the man who invented death.

Nagara attends the opening ceremony of his technical school, but feels out of place. He sees Mizuho leaving her all-girls' school, but she brushes him off. He recalls what happened after blasting off into space, questioning if he ever really went adrift.