Rinko lives with her husband on a solo business trip and lives with her son Makoto. One day, he was sympathetic to Makoto's classmate Yuki and treated him kindly... With a secret desire emerging, Yuki takes advantage of the gap in her kindness and forces her to have a relationship. Rinko feels guilty about having an affair with her son's classmate, but her body, which she has experienced for the first time in a while, can't contain her excitement. His body sought joy as he relentlessly toyed with caresses, and gradually awakened his inner carnal desires...