In some parts scattered around the world, 'Sha' is often used as a slang to address your friend, but in a distinct tone.
Often used when you're frustrated while ending the sentence and the last syllable is stretched or when used in the start, it is almost when you really want the person you're addressing's attention.
"Ay Marc, Ms.Ruben just told us she takin gym class tomorrow"
"Tell me you're fucking trolling Sha"
" Sha I'm telling you, that chick is into me"
"Ight man whatever you say"
"Im being fr Sha"