Mushi-Shi: Bell Droplets

Ginko stumbles upon a young girl in a mountain with branches and leaves growing out of her body. He later realises that she is the lord of that mountain but finds it strange that a human like her was chosen as the lord. He meets her older brother who has continued to search for her ever since she disappeared while accompanying him on a stormy day. The story is about that girl, Kaya, and how she is torn between continuing her duty as a mushi lord and returning back to her loving human family.