Double Dragon 3, Who is Chin's Brother?

In Games

Well this qeustion isn't that much important, but since some the best, if not the best, NES experts are here, I guess it wouldn't hurt to ask this question.

In the game, in stage two, the boss ( Chin ) says that the Double Dragon's killed his broter in their battle with the Shadow warriors. I played all the Double Dragons and could not figure out who Chin referred to.
Can someone put an end to my curiosity?

I don't know much about the third game, but in Double Dragon II (where they are fighting the Shadow Warriers) there's also a character called Chin. So if Chin is their family name that would make sense that they were brothers.

Chin is the guy on the first game that has the shaggy hair. He wears the purple pants, and you fight him on top of the unfinished building on level two. There are more than one of him, but that's the character known as Chin.

I find this game frustrating, i like Double Dragon II and Double Dragon III but Double Dragon II is easyer IMO.

Really good game if you give it a chance at first, because the very first level is already hard to beat.