The father disappeared when she told him she was pregnant. Despite opposition from those around her, the son worked hard and raised his son alone as a single mother. When her son got a job, she felt lonely. Then one day, her son invited her on a trip to a hot spring. The pessimistic mother reexamines her life. A twisted love between mother and son is born between the mother and son who encourages her. The mother's busty, voluptuous body...the son's large, impressive penis...the two desire each other and open the door to a forbidden relationship. A tender yet passionate story of incest between parent and child.