Since her parents passed away, Princess Mona lives by herself in a castle with two hideous, ghastly characters, Goomi and His Lordship. One day her sobs draw the attention of a unicorn, called U, who wants to comfort and protect Mona for as long as she needs. U becomes Mona's companion, her confidant and her inseparable friend. While Mona grows into a beautiful princess, a group of charming, peaceful and fanciful Yeah-Yeah’s settles in the neighboring forest. They have no particular special powers, yet they soon bring about major changes in everyone's lives, especially in Kulka, the dreamy musician.
Unfortunately the movie U is not yet available on HBO Max.
| Directing | Serge Élissalde | Director |
| Writing | Grégoire Solotareff | Writer |
| Sound | Sanseverino | Original Music Composer |
| Art | Serge Élissalde | Storyboard Designer |
| Art | Grégoire Solotareff | Graphic Designer |
| Art | Grégoire Solotareff | Decorator |
| Writing | Serge Élissalde | Screenplay |
| Production | Valérie Schermann | Producer |
| Production | Christophe Jankovic | Producer |
| Crew | Céline Kélépikis | Editorial Staff |
| Sound | Jean-Marc Lentretien | Sound |
| Sound | Bruno Seznec | Sound |
| Writing | Grégoire Solotareff | Story |
