Two exes reunite after 7 years, with both of them going through tough times and missing each other.

Hiyori wants to use Kaiji's sperm to get pregnant. He does it and uses it to film a birth documentary, on the condition he abandons any romantic feelings.

Hiyori made this plan to get publicity for her mother's manga. Kaiji can't help but kiss Hiyori and the relationship becomes distorted.

Kaiji and Hiyoru track down her sister, suspecting her mother is poisoning her; her mother appears.

Noriko is in love with Kaiji; Tamao and Michi suspect Hiyori is pregnant, but she wants it a secret; there is a traitor in the group.

Kaiji tries to save Hiyori, but she is unable to escape and goes missing for three months.