Rie is in despair after splitting up with her husband and getting fired from her job. Her son Shinichi is worried about his emotionally exhausted mother and takes her on a trip to a hot spring. During the trip, the son notices his mother, who is in a weak state, as a member of the opposite sex. He confesses his feelings and says, "From now on, I want to support you, Mom." Rie is weak and takes advantage of her son's kindness, and they end up having a relationship...