Kanojo no Imouto no Azato Yuuwaku: Junai Nante Gomi desu yo Senpai
Overview
A reverse NTR visual novel, where pure-hearted bookworm Naruse Shuya cherishes his innocent romance with his girlfriend Hazuki Akane...until her sister Fumino seduces him, escalating his desires that threaten to shatter his ideals of pure love.