In a fairy tale come to life, the clumsy, sweet, and gentle Ahiru, a duck transformed into a human girl, discovers she has the magical ability to transform into Princess Tutu, a beautiful and talented ballet dancer. Using her egg-shaped pendant, Princess Tutu can relieve people of the turmoil in their hearts through her dances. With this newfound ability, Ahiru accepts the challenge of collecting the lost shards of her prince's heart, which he had shattered long ago to seal an evil raven away for eternity. The fate of the fairy tale hangs in the balance, determined by the heroes' beliefs, feelings, and actions, as they struggle against their circumstances to achieve a "happily ever after."