Rinko lives with her son, Makoto, because her husband is away on his own. - One day, when Makoto feels sympathy for Yuki, Makoto's classmate, and treats him kindly... - Yuki, who has developed a secret desire for her, takes advantage of her kindness and forcibly begins a relationship with her. - Rinko feels guilty for having had an affair with her son's classmate, but she can't suppress the excitement that she feels for the first time in a while. - Her body seeks pleasure from his relentless caresses, and her inner lust gradually awakens...