My dear wife Yukiko has been under pressure from her mother-in-law about not having children yet. One day, our entire family decides to go on a hot spring vacation together. However, before the trip, my mother-in-law orders Yukiko to abstain from sexual activities for one month due to their childlessness. On the day of the trip, when we arrive at the hotel, both my father-in-law and I are rejected by our wives for intimacy. Feeling frustrated and aroused, they decide to relax their bodies in the hot springs. To their surprise, my father-in-law accidentally catches a glimpse of Yukiko's naked form while she was bathing...