Recently, her husband has been coming home late, leaving mother Reiko restless and uneasy. Convinced that another woman is sucking her husband's cock, her mind spirals into turmoil. Night after night, she finds herself sucking a vibrator, imagining it's her husband's cock. One day, she catches her son Shingo constantly masturbating and snaps, yelling, "You're always jerking off!" before impulsively taking Shingo's cock into her mouth. The shock and confusion ignite an uncontrollable chain of events.