A married woman who obtained a backup key, and her solitary apartment where she had sex with a male student until graduation. (Mukai Ai JUQ-618)

Yutaro, who lives alone, meets Ran, a married woman, at a nearby izakaya (Japanese pub). She has a strained relationship with her husband, but after drinking together, they become intimate and eventually have a physical relationship. Yutaro gives Ran his key, and Ran goes to his house with shopping bags while her husband is at work. To alleviate the loneliness caused by her marital discord, she spends passionate moments in the young Yutaro's room…