Aya is married to a man who has a child from a previous marriage. She has a good relationship with her already adult child, Yuya, and lives a fulfilling life. However, she is beginning to feel lonely and unfulfilled, as her relationship with her indifferent husband is not satisfying... Then, her husband is sent on a long-term business trip, and she and Yuya start living together unexpectedly. They suddenly become strangely close, and Aya gradually begins to feel uncomfortable as he becomes more physically affectionate with her. She tries to distance herself, but Yuya becomes increasingly bold...