Princess Tutu (2002)

Ahiru (literally 'Duck' in Japanese), is a young girl in a junior high school's beginner ballet program. She's prone to stammering and clutziness. She has a huge crush on her senpai, Mytho, a melancholy young man who doesn't speak much. Ahiru discovers that Mytho is actually the prince out of a story written by the mysterious Drosselmeyer. When Drosselmeyer died, the prince and the evil crow that were battling in his novel escaped. The prince defeated the crow, but only at the expense of shattering his own heart. Mytho is a boy without feeling or understanding. Drosselmeyer, however, has somehow returned, and has offered Ahiru a chance to help Mytho. She must become Princess Tutu, a magical ballerina, and help reclaim the pieces of her prince's heart. There is a catch, of course--Mytho is being controlled by his roommate Fakir, also a dancer, who seems to want to keep the boy soulless and heartless. Drosselmeyer also told Ahiru that a certain dream she's been having is real. She really is just a little duck, and has been transformed into a girl only so that she can become Princess Tutu. If she starts stammering-- quacking like a duck-- she'll turn back into one.