Dragon Knight

From Ivyscan:

Rin, a girl fresh from the country, is discovered by Dragon Knight Grian to be the new Star Princess, whose job it is to bring good harvests to the kingdom through her prayers. Rin's powers awaken as she tries to bring the barren lands back to life in order to cure the curse that eats away at the Dragon Knights. However, more and more questions turn up!! Rin finds herself caught up in the mysterious murder case of the previous Star Princess, Fionnuala! What does the future hold for this country girl?