Nasa and Tsukasa’s newlywed life has finally begun. The two of them head to a bathhouse run by a girl who went to middle-school with Nasa, Arisugawa Kaname. Kaname is shocked to see Nasa with a girl, and is curious about what happened after learning about the marriage. Meanwhile, Tsukasa heads into the bath and encounters Kaname’s sister Aya. When she asks Tsukasa about her connection to Nasa, Tsukasa replies that they are family.

In an attempt to help pave the way for Yanagi-sensei's wedding, Nasa ends up teaching a programming class at a girl's high school.

Gekko Kaguya is Nasa's brightest, and most mysterious new student. What is her connection to Tsukasa, and what might it mean for the future?