Imouto Choukyou Nikki ~Konna Tsundere ga Ore no Imouto na Wakenai!~

The protagonist, a die-hard eroge fan, is into "exposure," "rape," and "training."
One day, his real sister, Himeki Ichinose, snapped at him.
"Shut up and train me if you're such a nerd!"
Though it made no sense at all, this bizarre training life between brother and sister suddenly began.

Translated from dlsite