Ryuu ga Yonda Musume

Ten-year-old Mia lives with her aunt in the poor, secluded, so-called "Criminals' Village" where the only way out is to be called by a dragon and carried off to a new life. One day, the unassuming Mia is chosen for this honor and whisked away on dragon-back to the royal palace, a dazzling world filled with witches, dragon-riding knights, and a centuries-long curse she must somehow find a way to lift.

(Source: Kodansha USA)