I drew the original sketch for this a very long time ago, and I dusted it off for this portfolio I'm making. These people are loosely based off the Ainu, a people native to Japan. They have darker skin than other Japanese people, and came from a different culture.
I imagine this being set far after the end of the series, when the different nations have started to crossbreed a little. I'm a sucker for heterochromatic eyes. ;D
Additionally, the Ainu are descendants of Caucasians that had migrated through Asia, though more in depth information about this matter I lack.
This is gettin faved for epic beard.