Tatsuya sees off his daughter-in-law, who is about to give birth, and works housework. At that time, when I was feeling lonely in the empty days with no one to talk to, my daughter-in-law's sister, Maina, came to see how I was doing. Tatsuya, who is happy to have someone to talk to for the first time in a long time, welcomes Maina, but ... Maina's real purpose was her body. Maina suddenly burst into the bath. There is no way left to resist Tatsuya, who has lost his escape and is pressed by his elastic whitening boobs.