The humans who have strong Asian Blood running through their veins.
The most prestigious would be the ones that have all their ancestry roots in Asia.
The brotherhood serves as a swear stone for any Asian, meaning if someone swears upon it and is an Asian and they break it their disrespecting their ancestors and no Asian should trust that person again.
"Dude, no I would never betray my fellow Asian"
"Do you swear on the Asian Brotherhood?"