Feeling empty in her sex life with her selfish and overbearing husband, Mirai, a wife, has recently started satisfying herself on a daily basis. Unsatisfied with her own fingers, Mirai secretly buys a vibrator online... but her father-in-law, Kozo, finds out! "Can you teach me how to use this, Mirai?" Kozo presses Mirai. Frustrated and throbbing, Mirai is made to climax over and over again by Kozo's forceful attack...