The World of That Otome Games is Tough for Us summary:
Leon was reincarnated in the world of an otome game that he was forced by his sister to conquer just before his death. He tried to live a peaceful life as a mob character, but he encountered a scene where a female student ignored the flow of the story and tried to become the main character. Leon ended up seizing Marie, a girl who had a similar atmosphere to his sister from his previous life, and succeeded in thwarting the scheme. It should have have been the right choice... but why was he feeling uneasy about it?