Koushaku Reijou no Tashinami

A woman who plays otome games but avoids romantic entanglements in real life is struck by a vehicle after finishing work. Rather than dying, she awakens in the fictional world of a game she had recently played. She does not return as the main character, the central figure in the game's harem, but as the villain. She begins her new existence at the exact moment the villain is being exiled to a convent, where she is sentenced to spend the rest of her life.