Kuroha, Rue

黒羽るう

Rue is a character who is very hard to interpret. At the start of the story, she is with Myuuto more out of habit than for any other reason, but when Myuuto is threatened with being taken from her by winning his heart, she realizes she truly cares. As she becomes aware of her own feelings, and Myuuto is drawn further and further away into Princess Tutu's embrace, another aspect of her emerges.
In reality, this other side is Princess Kraehe, the daughter of the Raven. She is constantly told that only her father and the Prince are capable of loving her. Therefore, in an attempt to secure love and self-worth, she acts against Princess Tutu. Frequently, she makes it more difficult for Ahiru to return the pieces of Myuuto's heart. At other times, she kidnaps the Prince to lure Ahiru into traps. Her motives are solely to gain a sense of worth; nonetheless, she is not a weak villain and poses a significant threat to the rest of the cast.
In the manga:
Rue Kuroha is not the Raven's daughter. She is simply an ordinary schoolgirl who was given a pendant that allows her to transform into Princess Kraehe. However, as in the anime, Rue loves Myuuto deeply. By the end of the manga, she and Ahiru have become friends (and rivals in their pursuit of Myuuto's love).