A decade into her marriage, Hitomi, an ordinary housewife, lived a seemingly uneventful married life, save for the absence of sex. However, the surprise her husband prepared to celebrate this milestone was a couple's training interview at a mysterious, unfamiliar facility. Her husband, who had never before expressed any masochistic desires, gradually has his hidden urges unlocked under the guidance of a trainer. Forced to expose her most intimate and shameful self in front of her husband, Hitomi writhes in both physical and emotional torment, yet simultaneously discovers intense pleasure. In this way, their relationship transforms into something entirely new—revealing the authentic form of marriage this couple truly desired.