She gets sucked into a set of duels to own the Rose Bride and to revolutionize the world. The main character decided that she would become a prince and help princesses because when she was little a prince saved her when she was utterly depressed. Revolutionary Girl Utena (and the move, Adolescence of Utena) - an oldy but a goody, though there's a ton of symbolism so it can get really dense or strange at times. The only thing is that the anime covers a fraction of the manga and it just jumps right in with very little backstory so the first several episodes are really rough. For secondary characters there's a transwoman and a gay boy, and I think one of the others is bi but nothing is ever stated one way or the other. Hourou Musuko (Wandering Son) - one main character is a boy who wants to be a girl the other is a girl who wants to be a boy.
Aoi Hana (Sweet Blue Flowers) - it's a simple slice-of-life where the main characters are a teenage lesbian and her best friend from kindergarten who she lost contact with after moving to a different town.
