Sarah is Ciel's twin sister. Ciel has been keeping Sarah a secret ever since their manor burned. The only people who know she exists are the servants and sebastian and of course Ciel. She's a demon like Sebastian and a has made the same deal Sebastian made with ciel. Later on Ciel gets a letter from the queen, to help solve murderings that has been happening there. They get sent to Ouran Academy, where they meet the host club. I do not own black butler and ouran highschool host club. I hope you all like the story!