Husband and Yukari find their married life falling into monotony. When they learn that a neighbor next door in their apartment building has opened a massage parlor, the husband comes up with a plan—he suggests sending his wife to receive a massage. Watching the entire session through a hidden camera, he begins experiencing an unprecedented thrill and arousal. As he observes subtle changes in his wife's emotions during the massage, he becomes increasingly obsessed with the idea of her being taken by another man. A new, forbidden dynamic begins to grow between them, pushing their relationship beyond the boundaries of ordinary married life.