While his parents are away on a trip, Koji is looked after by Mary, his mother's close friend. She turns out to be far more beautiful and captivating than he ever imagined, and Koji finds himself unable to take his eyes off her. With little experience around women, every move Mary makes feels like magic to him, drawing him in completely. Desperate to share a special moment with her, he comes up with the idea of using her lingerie for masturbation. But his plan backfires when she catches him red-handed, and he panics, trying to cover it up. Instead of getting angry, Mary teasingly turns the tables. "Didn't you want to do something naughty with me?" she asks innocently, leaving Koji even more flustered and aroused.