A secret affair with Asahi Mizuno's mother-in-law: Asahi Mizuno lives alone to raise her children and now her adult daughter has her own family. One day they went to Asahi Mizuno's house to play and slept over. Somehow, Asahi Mizuno and his son-in-law were having intimate sex together right at this time. Especially when they have sex right next to that girl, how will things be discovered afterward, or how things will turn out?