Akizuki Shizuko, 41 years old. She has a stunning waistline, but beneath it lies a surprising body curve. Her husband has been transferred overseas alone, leaving her in a long-term sexless marriage. One day, she visits her husband's family home by herself. There, a certain secret awaits that will drastically change her life. Suddenly confronted with a man's erect penis, she can't hide her shock and confusion. Yet, as Yūko stands there, she becomes increasingly drawn to this "massive cock," her eyes unable to look away.