Chisa's husband is busy at work and ignores her, making her sexually frustrated. Her husband's younger brother comes to visit. Taking advantage of his absence, he pressures Chisa into a physical relationship. Chisa is taken aback by this sudden turn of events, but her lewd body, left alone by her husband, responds to her brother-in-law's caresses and she allows the relationship to take place. From then on, her brother-in-law takes advantage of her husband's absence to visit the house. Chisa knows it's wrong, but they continue to have sex. Then, her brother-in-law suddenly stops coming to the house. At that moment, she realizes that she has been expecting his visits...