His mother, Shoko, worries that their relationship won't last because she doesn't know how to interact with her new girlfriend. "If you can gain some confidence in sex first, everything else will be easy," she tells her son, who has little sexual knowledge. She uses her body to teach him how to deep kiss with tongue entanglement and how to play with the sensitive parts of the female genitals. The lesson then finally extends to penetration, and the son gains confidence and goes on a date with his girlfriend...