Megumi, a married woman living in her husband's family home, has been cheated on several times, which has caused her to distrust him. Her brother-in-law, whose work is not going well, returns home to her husband's family home for a short time. One night, the brother-in-law, who has been struggling both at work and in his private life, witnesses his younger brother and his wife having sex. In the sweltering summer heat, Megumi's sweaty, ripe, big breasts shine brightly, and the brother-in-law loses his senses...