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.

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?