From ADV:
Ahiru wishes to become a beautiful ballerina, but her two left feet always get in the way of her dreams. All of that changes when she is given a magical pendant and is suddenly transformed into Princess Tutu, a graceful dancer who is lighter than air. But not all is well for the crowned princess of pirouettes. The boy of her dreams has a broken heart, and Tutu must collect the shattered pieces to make her beloved Mytho whole again, before a darker dancer takes his heart away forever.