The Big Sister I Admired Was an Otokonoko

A Japanese adult visual novel featuring Minase Haru, a protagonist who discovers that the school idol he has long admired—who he believed was his older sister—is actually his cross-dressing brother. After Haru's true feelings are revealed and accepted, the two siblings explore their newfound relationship through romantic and sexual encounters, including cosplay scenarios at school. The game follows their journey as Haru awakens to new desires within their incestuous dynamic.