[China] Imouto wa Doujin Shoujo Cosplay Kei Ch.1-4 [biribiri]

Onii-chan faces a ridiculous predicament when his bossy little sister, whose obsessive doujinshi cosplay club is desperate for new material, drags him into the clubroom to serve as her guinea pig for "lovestruck expression" practice. Things escalate rapidly as her playful teasing turns into something much more stimulating, with her ample curves bouncing as she straddles him while demanding he show her what real seduction looks like. Things get even more chaotic when the stern student council president, Ayumi, catches them in the act and tries to shut down the "lewd" club, forcing Onii-chan to navigate a wild, deflowering day filled with busty cosplay girls, glasses-wearing senpais, and plenty of stockings and gloves—culminating in an invitation to a secret after-school "lovestruck" gathering.