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.

Ai, Neiru, Rika, and Momoe are quickly becoming close friends as they continue to protect Eggs. But as they grow closer, questions pile up and tensions rise.

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.

It’s Rika's birthday, and the girls get together to celebrate. Rika, however, is focused on her troubled relationship with her mother, and those worries carry over into her next battle. Will she be able to overcome her inner demons in time?

The girls are surprised when Neiru invites them all to her house, and even more surprised to find out that she lives at her company. Is Neiru ready to be open about her situation, and how will the others take it if she is?

Ai, Rika, and Neiru confront Acca and Ura-Acca, but are distracted by shocking news from Momoe. Later, Momoe confronts her toughest battle yet while Ai makes a difficult decision.

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.