The Kazama couple are in their third year of marriage. They were passionate when they first got married, but recently their sex life has become stale. In an attempt to improve this, the husband prepares a vibrator, but his wife Yumi scolds him for relying on tools and puts it away in the cupboard. One day, Yumi, a returnee who is fluent in English, is asked by her nephew Toshio to teach her English. A few days later, Toshio visits the house and they immediately begin to learn English, but by chance, Toshio finds the vibrator that she had put away in the cupboard...