Aneki... My Sweet Elder Sister 3

Adapted from the manga series by Yoshu Ohepe. Takumi can't seem to get enough of Saki's luscious senpai's form, which makes her stand out in every setting. She meets him on the train one day, and the two become fast friends. Takumi glances at her shape whenever he has the opportunity, always getting a hard-on. The next day, he discovers that they both share the same fetish... and so the narrative starts.