Nanami, a wife, is a little depressed when her husband's boss, the Kayamas, and his wife decide to go on a hot spring trip. However, they soon get to know each other and spend a pleasant time together... However, Kayama cannot forget the warmth of his touch when he accidentally touches Nanami, and in his anger, he attacks her while she sleeps. Unlike her indifferent husband, Nanami climaxes again and again from the relentless caresses of the middle-aged man and the tingling stimulation. Once she has experienced the pleasure, her body begins to be Kokoro, and she cannot resist the rising desire...