A wife named Sayu who feels lonely every night because her busy husband no longer pays attention to her. One day, while trying to satisfy herself alone as usual, she is caught by her perverted father-in-law. Although she initially opposes, her long-suppressed loneliness and desire make it impossible for her body to reject him. Her father-in-law gradually becomes more aggressive in using her, eventually bringing in his acquaintances to gangbang her. At first, Sayu opposes, but she gradually grows accustomed to the situation. In the end, she begins to beg for it herself, and her father-in-law happily fucks her whenever she asks.