Yuki: Snow Fairy(1981)

Yuki

Up in Heaven, Yuki’s grandparents decide that, having turned thirteen years old, she must go down to Earth to a village that is torn by bandits and intervene to save its people. However if she does not succeed within one year she will become as insubstantial as the wind. Down in the village, Yuki is befriended by a group of orphans whose parents have all been killed by the bandits and who now subsist by begging. Yuki amazes them by taming the wild horse Blizzard. She is instrumental in getting the orphans and farmers to stand up to first the warring bandits and then Goemon, the greedy lord that owns the region. But Yuki must face her greatest challenge yet when the displeased Demon God that lives in the volcano emerges to destroy those who live beneath.

(Source: moria.co.nz/fantasy/yuki.htm)