FERA-134 Yumiko Mitsuse, a mother who thought it was okay to have sex just once, but ended up in a swamp after her son kept making her cum.

``I can only ask my mother...right? Isn't that good? Hey, tell baa!!'' After being scolded by his girlfriend for being bad at sex, Koji asks his mother, Yumiko, to use him as a practice table. - ``I understand...but in return, it's only once.'' Yumiko refuses several times, but ends up giving in to Koji's enthusiasm and accepting him. - "It's no good...please stop!" Yumiko regains her senses and resists this unforgivable act, but Yumiko's gentle caress gradually causes changes in Yumiko's body and she reaches climax over and over again...