Father-in-law Kanichi constantly leered at his daughter-in-law, Kayako, with lustful eyes. Amid her exhausting days of housework and caregiving, she could no longer ignore his lewd advances. When her husband, Chusuke, leaves on a business trip, Kanichi's perverted desires explode—he spies on Kayako while she bathes, his gaze crawling over her body, and under the pretense of caregiving, he orders her to clean his filth with her mouth. Though reluctant, Kayako finds herself emotionally vulnerable in her husband's absence, her aching body soothed by the perverse care she receives. When their son, Atsushi, discovers what's happening, feelings of hatred and jealousy toward his mother begin to stir, twisting the family's bonds into something far more complicated.