Yumiko and her son, who moved to Tokyo for university, went on a hot spring trip during summer vacation after a long time. Actually, after her son moved to Tokyo, Yumiko's husband's infidelity was discovered, and their marital relationship suddenly turned cold. They were no longer in a marital state, and divorce was imminent. This trip was intended to inform her son of this fact. During the journey, Yumiko told him about the divorce. Learning that his mother would belong to no one, her son began to desire her as a woman…
