Kyouko is a married woman who lives with her son while her husband is away on a business trip. One day, her son's friend, who came to stay with her to study, witnesses her masturbating. He forces her to have sex with him. The young friends play with Kyouko's body many times, making her cum and having sex with her, hiding it from her son. Kyouko's body becomes immersed in a pleasure she had forgotten for a long time...