Ahiru is a 13-year-old ballet pupil who exemplifies clumsiness despite being good-hearted and sweet. However, Ahiru harbors a significant secret. The enigmatic Drosselmayer transformed her from a duckling into a girl to undertake a critical mission - to aid a Prince in retrieving his scattered heart fragments. In her transformed state as Princess Tutu, Ahiru employs her mystical dances to alleviate anguish and cleanse negative emotions.