War of Rain :

Fifteen year-old Miri lives in a desert village called Boreala, which competes with the city of Stratos for Rain – the equivalent of Holy Water. During a confrontation while gathering Rain, Miri accidentally kills a citizen of Stratos, and unintentionally starts a heinous war. Now it is up to her to find the God of Rain, Kalono, and ask Him for an invention that can bring both peace and war before Boreala is destroyed.