Married and living with her husband's family, Akari, a housewife. Her brother-in-law, who had temporarily returned home after struggling with his writer's job, was leading a troubled life both professionally and personally. One night, he witnessed the intimate moments of his younger brother's marriage. Overwhelmed by the sweltering summer heat and the glistening, sweat-soaked mature body, he lost his reason... Unable to restrain himself, he commits an act against his sister-in-law, yet somehow Akari is drawn to him. On a tropical night, the two engage in intense sexual intercourse, drenched in sweat and bodily fluids, mutually seeking each other.