The son loves his mother. One day, the three of them go on a trip to a hot spring, but the father has to return home due to an unexpected call from work, leaving the mother and son behind, and the atmosphere becomes tense. While the mother is taking a bath, he invades her with his erect penis. His erection is so intense that the mother tries to dissuade him with her mouth. Just when the mother thinks she can relax, her desire grows even hotter, and she ends up mating with her son. However, it doesn't end there.