Akari is a married woman living with her husband's parents. Her brother-in-law, a writer, has come home to her husband's parents' house for a short time after his job as a writer has not gone well. One night, the brother-in-law, who has been struggling with both his work and personal life, witnesses his younger brother and his wife having sex. In the sweltering summer heat, Tomoka's sweaty, ripe body is dazzling, and the brother-in-law loses his senses... Unable to resist, he rapes his sister-in-law, but for some reason, he is attracted to his brother-in-law. On a tropical night, the two of them, covered in sweat and bodily fluids, have an intense sexual encounter.