I think the fact that we see them on his chest when he's just kinda lounging around in the cover pages also indicates he's an ink fiend, though the tattoos themselves look like they should have some kind of meaning.

The art in Togari looks really rough, but(like mushishi) somewhat like BotI, and the fight scenes look rather BotI-ish. In the bits I've skimmed, the lead looks like you could plop him in the middle of a conversation between Manji and Magatsu and no one would notice.

I just wish I weren't going into it w/ BotI thoughts, as I won't be able to resist comparing them...