Kanako's wisdom teeth have worsened, forcing her to undergo surgery and be hospitalized. To take care of her husband Yukihiro, who is left alone, Kanako's mother, Sayaka, comes to their house for a while... Yukihiro is spending time with his mother-in-law for the first time in a long time, and Sayaka is spending time with a young man, both of them feeling excited even though they know it's wrong. Then, one day, Sayaka Sayaka sees Yukihiro's erect crotch. The two panic, but the mishap doesn't end there...