Kaa-Chan No Tomodachi Ni Shikotteru Tokoro Mirareta

Naoki is a young man who enjoys cooking and watches a lot of porn. One day when the best friend of his mother, Shiori, is staying over she accidentally walks in on him masturbating. As fortune would have it, Shiori is aroused by the act and gives into Naoki’s advances. Shiori is quickly impressed by Naoki’s sexual knowledge gained from porn and virile stamina.