A woman who used to be the secretary of a former company president remarries a man who runs his own business. Worried about her stepson, who still lives at home even after reaching adulthood, she kindly takes care of him as a loving stepmother. One day, entering his bedroom to encourage him, she discovers her missing underwear—unaccountably vanished from the laundry—hidden in his room. Seeing her stepson panic and frantically apologize, she embraces him gently, troubled yet compassionate. But in an instant, overwhelmed by excitement, he pushes her down, and she finds herself on the verge of being penetrated…!