Yumiko's sexual desire continues to increase with age, to the point where her husband's efforts alone are not enough for her as a sexually insatiable wife. Nevertheless, a major incident occurs where her husband becomes impotent. In this emergency, Yumiko encounters her son Katsu's aroused penis as he enters puberty and cannot restrain herself from pouncing on him. However, Katsu quickly ejaculates upon encountering her mature body. Feeling completely unsatisfied, Yumiko uses a cleanup blowjob to strongly arouse him again and re-inserts him into her vagina...