Mr. and Mrs. Tsuruta moved to her husband's parents' house to buy their own home. Her father-in-law, Bungo, who was divorced at a young age, lives alone at her parents' home, and he happily accepts them. One day, when her husband is alone on a business trip, Mai's lustful father-in-law, who had been watching for an opportunity, pushes Mai down. The father-in-law's desire remains, regardless of Mai, who is forced into a relationship and sinks into deep sadness.