Her husband, Tatsuo, began to feel unwell for several years. His wife, Reiko, was busy taking care of him. One day, her only daughter, Asuka, and her husband, Hayato, invited her to a hot spring trip, which they said would be good for their nourishment, and they readily accepted... As they arrived at the hot spring resort with its clean air, Tatsuo's smile gradually increased. Reiko, watching her husband, also took a bath to relieve the fatigue of caring for him. However, Reiko did not know that a few hours later, a "disaster" would befall her...