Aaaaah!?

[Mimeblade]

lol, I have a hard time picturing straight-laced Kenshiro acting like a total thug.

His Uncle smokes...that's another thing I find...weird. I mean, I thought smoking was bad for martial artists but....jeez.

It's like you could picture a super martial artist crouching down in the back of a school yard, smoking a cig, and wearing a huge elvis afro.

Messed up.

[donoghu]

The reason why a lot of the best martial artists smokes in this manga is explained by Kenshiro. (Can't remember the page or chapter thought)

Once the japanese guy who help him around Shangai (the one with the moustache) ask him why is he ruining his life with that "crap" (cigarette) and Kenshiro answer that he loose so much blood on a basic (being wounded everywhere) that he needs to keep his blood dirty to help it able to keeps its regenerative features. (Dirty blood is naturally forced out of the body and exchanged with new blood.)
You don't need to understand more than that.