Ai Ohto becomes withdrawn after the death of her best friend, Koito Nagase, and has not been attending school since.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...