Adult PC Game: Ona Ken! -International- Ver.1.00 Itchby FruitsJam Archive

Kasukabe Nao, who masturbates every day, decides to form a club to discuss masturbation, so as to get new ideas for the ultimate masturbation. She forces her friend, Natsuigawa Hibiki, her classmate, Akiru Norika, and an upperclassman, Fuyutou Mako, to join her in the club.