The Domain of Children.Ai Ohto becomes withdrawn after the death of her best friend, Koito Nagase, and has not been attending school since. While walking late at night, Ai is led into a garden by Acca and Ura-Acca, who give her an egg that they promise will grant her wish. When Ai breaks it in the dream, the egg hatches into Kurumi Saijō, a girl her age who committed suicide. Kurumi briefs Ai on the rules of the Egg World as they are attacked by Seeno Evils and Kurumi's Wonder Killer. Realizing her apathy had a role in Koito's death, Ai uses Kurumi's pen to defeat the Wonder Killer. Having successfully saved Kurumi, Ai learns that the more girls that she saves, the higher the chance Koito will return.