After many years of dormant rest, a hot springs fairy awakens in modern-day Japan. However, while she slept, she took on the appearance of a young girl. She decides to cooperate with the locals whilst trying to regain her powers.

http://myanimelist.net/anime/31143

Onsen Yōsei Hakone-chan (TV) - Anime News Network

https://www.youtube.com/watch?v=QTLDzb7TQ3E