Natsuo is on a hot spring trip with her current fiancé. The maid at the inn they visit looks just like her old lover. When she hears his name...it's her son who she gave up for adoption 22 years ago. She leaves the inn with her fiancé, but decides to stay a little longer and stay for one night. The son she gave birth to...how can she not love him? As her son washes her back and their skin touches, she can't help but feel the tingling sensation in her body due to the image of her old lover and the warmth of her son. Now begins a forbidden act of love that should never be crossed...