Mother Yumi had worked tirelessly on her own to ensure her daughter Ami's happiness, and her efforts finally paid off when Ami found a good marriage and wed. Seeing her daughter's joyful life, Yumi genuinely rejoiced and lived each day with contentment. Yet deep inside, her own desires as a woman still lingered, refusing to fade away. Especially whenever she became consciously aware of her son-in-law, Hirofumi, as a man, an uncontrollable excitement welled up within her, forcing her to calm herself through secret self-pleasure. However, she never expected that these private moments would one day be discovered by Hirofumi himself.