Forty-two-year-old Sayoko Kuroki has been married for fifteen years, living an ordinary life in public housing. However, suffering from a sexless marriage, her daily frustrations and unmet desires continue to grow. One day, her neighbor unexpectedly discovers her, forcing her to masturbate in front of him. As acts like handjob and blowjob gradually escalate, Sayoko's emotions begin to tremble and unravel. When the neighbor's older brother notices what's happening, he seeks revenge by sexually humiliating Sayoko.