A young man returns to his hometown and is greeted by his father and his kind neighbors. He quickly becomes close with the wife, Mayu, as they used to be good friends. One day, Mayu notices the young man's erect penis while he is sleeping and seduces him, inviting him to have an affair. And so begins the adulterous sex... Even the thrill of being found out by her husband becomes a pleasure, and the story of a summer spent by a young man and a married woman who lose themselves in sex and go wild...