Six years into her marriage with an older husband, Aki finds herself emotionally and physically starved, longing for intimacy. One day, her husband brings home his superior, Sagawa, who confesses that he too has long been estranged from his wife in every way that matters. When her husband falls asleep, Aki and Sagawa continue drinking late into the night. In a moment of vulnerability, Sagawa pulls her into an embrace. Feeling a man's warmth for the first time in years, Aki hesitates at being touched by someone other than her husband—but her body betrays her, responding instinctively. From that night on, they begin meeting in secret whenever her husband is away, slowly nurturing a forbidden affair that awakens desires she thought long buried.