There's an old costume shop in town, which has been there for generations. Obviously, this store isn't quite as other costume stores: Their costumes are magical. Some costumes have simple magic on them, they simply fit perfectly on anybody who tries them on. Others subtly change you, so that you look more like whatever you dress up like, and it runs all the way up to costumes that not only change you, but also affects the world around you: You become what you dress up as, and reality changes, or you are moved into a reality, that matches and accepts you as what you now are.
Who comes by?