Five years ago, in Asakusa, Robin, Haruki and his racer sister Kiriko had spent their days happily living in an orphanage.

Tokio is taken to see some bizarre-looking babies, and realizes just how little he understands about his surroundings. On a boat with no escape, Maru and Kiruko suffer a terrifying attack. As all is failing, it is up to Kiruko to devise a new strategy.

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.

Maru and Kiruko are on the hunt for the Immortal Order. On the way, they stay at a hotel run by a girl named Totori. Dumping their bags and searching for safe drinking water, they stumble upon a badly injured man.

Maru and Kiruko discover that Dr. Usami had a button with the same pattern as the logo they found on the Kiru-Beam. They decide to follow it's trail, and meet a mysterious informant along the way. Meanwhile, back at the nursery, an emergency meeting is held.

Maru and Kiruko head to the Ibaraki facility after Juichi gives them his car. Meanwhile, a group of new 5th years join the academy. Mimihime notices that one child called Ohma seems very lonely, and tries to make friends. But Ohma has special reasons for keeping away from the other children.