35-year-old Sumire Takaoka. For five years, she's lived with her husband in a sexless marriage, and as she grows older, her increasingly sensitive body finds release only through self-pleasure. One day, after bringing her drunken husband home, she gives in to uncontrollable desire and seduces his subordinate, Yamazaki. That fleeting impulse deeply affects Yamazaki, stirring up resentment toward her husband and a desire for revenge. He begins turning her into the company's shared fucktoy, using her body to retaliate against her husband's unjust treatment. This twisted obsession will drastically change the course of both their lives.