Minako desired children but suffered from a sexless marriage, resorting to daily masturbation to cope. One day, while masturbating, her nephew suddenly arrived carrying a keyboard, saying he wanted to learn piano. Minako began giving him lessons, but he discovered her mid-act. Embarrassed yet aroused, he became overwhelmed by her gentle guidance and ended up receiving creampie sex from her. An unexpected turn of events leads to Minako giving sex lessons to her virgin nephew.