Ahiru is an ordinary duck transformed into a ballet student by the mysterious Drosselmeyer, and given a pendant that lets her become Princess Tutu. As Tutu, she can help the prince Mytho recover pieces of a heart he shattered to seal away a monstrous Raven, dancing them back to him one fragment at a time. Her efforts draw the attention of Fakir, Mytho's protective roommate, and Rue, a girl who has loved Mytho since childhood and guards him fiercely.