Although is not bad a translation for "bro" IMO, we usually don't need those friendship "pronouns" because the greeting words in Japanese are diverse enough to distinguish those nuances alone, unlike English basically has only "hi" and "hey".
For example (translation is not decisive, requesting improvements _seriously_ ):
* : "Hi!", "Hi ya!"
* : "Hey bro!", "Wassup!"
* : "Hey dude!", "Hey man!"
* : "A-yo!", "Hey!"
* : (most "jock" style) "Yo!", "Howdy!", "'Sup?"
* : "Hey you!", "Yo!"
* : "Hey over here!", "Ahoy there!"
* : "Hello!", "Hi there!"
* : "What ho!"