Amefurashi: The Rain Goddess(2007)

Amefurashi

Gimmy is just an ordinary teen living in a desert town when his younger twin brother and sister disappear. While searching for them, Gimmy comes face-to-face with a sassy deity, Sora, the rain goddess who provides water to the town. But another goddess, Ciel, wants Sora’s sacred tree—so that she can control the rain!

(Source: Kodansha USA)