It's been two days since I sent my wife off on a trip. The living room was out of control. The savior who appeared was Kaho, the daughter-in-law's older sister. Although surprised by the sudden visit, Kenichi was still extremely grateful to Kaho for helping with the housework. That night, while Kenichi is relaxing in the bathtub, he is attacked by a naked Kaho. "Sister-in-law, what are you doing!?"