While watching her grandson take a bath, Miyuki has a strong sexual desire to take his grandson's clothes and indulge in masturbation with it. The reason why it is so popular despite having already gone through menopause was a long time ago, Miss Soap. One day, when he learns that his grandson is a useless virgin who can't go to the sex industry, he decides to do something to overcome his gynophobia. "Grandma will teach you step-by-step"