MAMOTTE! LOLLIPOP, by Michiyo Kikuta. First published in 2002, and first published in North America in 2007.
PLOT:
Nina dreams of finding a dreamy guy to protect her, but in the mean time she's happy to settle for sweets. When she confuses a magic pearl for a candy, her life is swiftly invaded by two magical boys, Zero and Ichi. They're wizards in training who need that pearl to pass their exam, so they decide to stay by Nina's side until their teachers can find a magic cure for her problem. Between the other wannabe wizards seeking to take Nina's pearl by force and her own growing feelings for the boys, Nina's sweet and simple life is about to be turned upside down!