First off, the word "nigga" has nothing to do with race. Its just a word you call your friends instead of "homie" "buddy" "dawg". Anyone can say it; blacks, whites, latinos, asians, dont matter, and if you think its a word only for black people, then you live in a very rich all-white snobby neighborhood. I'm white and I call all my friends "nigga", even the blacks ones.
White Guy: Whats good ma nigga??
Asian Guy: Nuthin much. *Pulls out blunt*
Black Guy: Yall niggas betta blaze that shit up!