Unjou Roukaku Kidan

Unjou Roukaku Kidan (雲上楼閣綺談) is a manga series by Sei Gotou.

Plot
Kasumi was given a name favored by the gods so she would always be protected. Yet, when there is a drought in her village, she's the one chosen as the human sacrifice to go to beg the gods for rain. Her parents are sad, but Kasumi goes anyway. When she gets to the heavens, they try to send her back, but she won't go until her village sees rain, and now she's determined to become a fairy of the heavens. If it'll take 1000 years to learn to ride the clouds, she knows she'd better start now!