The Sore Feet Song is the intro to Mushishi. It's original because it's relaxing, nice to listen to and short. These are three qualities not often found in anime intros.
Not only that this intro to Mushi-shi is performed in another language besides Japanese, specifically English. Not too many intros and endings are performed in other languages which makes this one of the quite rare exceptions
Well there are certain anime series where the openings, endings, or even both are performed in other languages other than Japanese and besides Mushi-shi too. One of them is Negima!? Both the openings and endings are performed in English for this series
