The story is based on a place called The Hidden Leaf Village. There are other Villages around the leaf Village like, Sand Village. If the story would have taken place in the Sand Village, the Headmaster wouldn't be named Hokage they would be named Kazekage.
If Kakashi lived in the sand village he would have been called Kazekage. But since Kakashi lives in the leaf Village he's called Hokage.

A year has passed since the fourth great ninja war and Kakashi's appointment as Hokage loons. But first he has to go to the Land of Waves for A Dangerous Mission rescuing hostages from a top secret Airship. There he confronts a ninja whose heart was frozen by tragedy.

There was a lot more that I had, but it wont let me post it all.