DASS-814 I met a beautiful, mature woman friend at a box health club and we ended up having an affair.

Tired of work and family, Shinichi visits a brothel due to discord with his wife Hitomi and dissatisfaction with his sex life. There, he happens to meet his mom friend Sarina again, and a secret relationship begins. Although confused at first, the two gradually begin to desire each other, and Shinichi is torn between his family and his desires. Eventually, the gap between him and his wife, who cares about her family, widens, and he finds it impossible to stop his secret meetings with Sarina.