Boku Wa Imouto Ni Katenai [English, Full color], by Miyasaka Miyu

Ready to fap? Oh, come on, don’t act like you’re shocked.
The drawings are SPLENDID, the female char is lovely, and the scenario is as simplistic as it can get (sister scores better at a test, asks onii-chan to crossdress, sex follows. Wincest ftw! ^^).

I’d say, it’s a great fap’n’go manga we’ve got here, very well drawn, with quality full-color art. Plus, I always welcome wincest.
Enjoy! ^_^ And thanks a LOT to LeGen!

–Update: there’s a volume 2, now

And now, the download & gallery links

Open the Complete Pictures Gallery

Or you can also use the Alternative:
Zip Mirror #1 – or – Zip Mirror #2