Satomi notices her son touching her body one night before he leaves home after finding a job. Unable to say anything, she ends up letting him stay over. One day during a long weekend, they decide to go on a hot spring trip together but... Son has always liked his mother. He can't resist her seductive figure and eventually convinces her to give in. At first, Satomi resists but soon gives in to the pleasure, taking her son's manhood into her mouth. This taboo story follows their incestuous journey as they continue to cross boundaries, seeking each other's bodies again and again!