Fifty-year-old Reiko Manda reaches her limit with her husband's behavior of bringing women home, and gradually finds herself drawn to the affection shown by her brother-in-law in daily life. Her relationship with him goes beyond mere friendliness, deepening over time as she surrenders emotionally and physically to him. This story captures Reiko's inner turmoil and emotional conflict as she becomes entangled in a whirlpool of adult desires.