Shikkoku no Shaga The Animation.

Ushiwaka is a young noble traveling the lands of Edo Japan where dangerous Yokai roam the land and meddle with the humans. On his way he is attacked by a pack of wild Yokai only to be saved by a Yokai woman, aiming to become a God one day, called Shaga. Shaga and Ushiwaka start traveling together fighting hostile Yokai and helping people and Yokai co-exist in harmony which proves to be much more difficult that it seems at first.