Ore no Imōto ga Saikō no Okazudatta

My own sister saw me masturbating in a younger sister erot*c game.

My younger sister, who always has a straight face, then somehow decided to help me masturbate. ……

She made my friends wank and even got the most beautiful girl in school to get involved.

Can I ever get a girlfriend now that I can only get off with my younger sister?

And why is my younger sister still watching me masturbate?

A popular web-based work has been completely revised and new scenes have been added!

(246 pages in paperback format)