A manga book. Fourth in series. I didnt' like it very much, but my younger sister did. Rating is Y, ages 10+
From back cover:
Sociable Chocolat and shy Vanilla were best friends until a cutthroat contest to determine who would be the next Queen of the Magical World ended it all. Since Vanilla has come out of her shell and embraced the Dark Magic of the Ogres, she's now the enemy of all witches, especially Chocolat. And the Ogres are making their move, crashing a magical festival and casting a dark spell on Chocolat's school. Though Vanilla has teamed up with the evil Ogre Pierre, Chocolat can't seem to get the boy out of her mind. How can Chocolat win the competition when she has a crush on an Ogre and still hopes to save her rival, Vanilla?