Yumiko is a lewd wife whose sexual desire continues to increase with age, and sex with her husband is not enough for her. Despite this, a serious incident occurs in which her husband becomes impotent. In an emergency, Yumiko encounters her adolescent son, Katsu's, erect penis and cannot resist jumping on him. However, Katsu ejaculates on her ripe body in no time. Not satisfied at all, Yumiko gives him a cleaning blow job to make him erect and inserts it into her pussy again...