Yo might have different origins and uses in English but one of the uses is the same as a Japanese girl would use it at the end of a sentence. Adding yo at the end of a sentence is a girlish way to talk, so dudes might not want to use yo while in Japan or people'll think they picked it up from their Japanese GFs. LOL Dudes who pick up Japanese from their Japanese GFs do tend to sound girly :)) But only someone who's fluent would pick up on the difference. I sometimes wonder if using yo at the end of a sentence got exported from Japan by dudes who picked it up from their GFs? :-?
Yo is also used like hey, which is another common usage. Not polite, but common. Saying yo yo when calling out to someone is more of a masculine usage, so you won't hear girly girls using it all that much. When I speak Japanese, I take on a more masculine tone, which friends find interesting since it's a pretty big contrast from how I look on the outside. I never did like the girly way of talking. :-?
I get weird looks from expats when I tell them I don't eat raw fish. They look at me as if I'm out of my mind. That's why I like the sushi go rounds they have here since the toppings aren't always raw fish and they have a pretty good variety that I can eat. Yeah, I'm a fussy eater so not easy to cook for :P
Speaking of cooking, my friend promised to bake me cookies :-? Dude, don't forget to bring freshly baked cookies the next time you see me, yo! :P