A young man, interested in doing research on urban regeneration to help repair his dystopian sci-fi future, comes to work for the genius Doctor Ginkaku, only to find he's retired from the country's research institution and taken up... super-elaborate sex toy development? What's more, he needs a guinea pig.

Kabu was told by his father, that he is going to succeed the Umezaki group, but he is hesitant to do so. On the other hand, Sagawa, who is regarded as the successor of the group by everyone else, tests Kabu’s loyalty by giving him an ultimatum, to give up his company or Nirasawa.
For Kabu, Nirasawa is not only a convenient pawn, but at the same time he’s a lover, that has captivated him with his unexpected cuteness.

Will Kabu really send Nirasawa away…!?

This story takes place 4 years after the events of Bi no Isu.