After 18 years of marriage, Hitomi is worried that her husband has suddenly become neglectful and is cheating on her, so she secretly masturbates to soothe her body... One morning, her husband's company manager delivers some work documents for her husband... Hitomi, who has let her guard down in front of the kind-looking manager, ends up having a fling with him while discussing her sex life with her husband. Worried that her husband will find out, Hitomi suppresses her voice and writhes in excitement as she has an unfaithful sexual encounter with the manager, reaching a climax for the first time in a long time...