Hime-sama Goyojin (2006)

Himeko Tsubaki is a normal schoolgirl leading a normal life. But one day, she crosses paths with two bumbling thieves Leslie and Karen, and accidentally comes into the possession of a magical crown that turns her into a princess (much to the chagrin of her snobby rich classmate Aoi). Unfortunately, this crown makes her a target for all sorts of bizarre characters: Leslie and Karen, a cult of cat worshippers, an assassin, and Princess Nana, the crown's real owner, who only speaks in a foreign language and has a mischievous pet monkey. Can Himeko make it through her new life of comedic chaos?