A pair of mysterious voices lead 14-year-old Ai Ohto to a strange egg, promising her a chance at what she wants most. What's inside the egg? And what does Ai really want?

While buying Eggs for herself and Neiru, Ai meets Rika, a former idol who is there for the same reason. Rika quickly pushes her way into Ai's life, but what lies beneath her cheerful and callous exterior?

With Rika out of action, Ai is on the run and struggling to protect two girls from the most devious killer she's faced yet. Meanwhile, a fourth child is also fighting to protect the girls in the Eggs.

The girls are attacked by a dangerous new type of enemy while trying to protect their Wonder Eggs. Acca and Ura-Acca may have a solution, but Ai is more concerned with the budding relationship between her mother and Mr. Sasaki.

The girls realize that there's more waiting for them at the end of missions than they bargained for. As doubts pile up and tensions rise, Ura-Acca decides to tell Ai his story.

Ai, Neiru, Rika, and Momoe have all cleared the game, but what awaits them isn't quite what they hoped for. With their long battles behind them, what future will each girl choose?