Something I just realized is that Shiro doesn’t smoke.
He is exactly the sort of Disaffected, Brooding, Dark and Mysterious, Too Cool For School lone wolf who normally would smoke.
He’s even immortal, even more so than X-Men’s Wolverine.
But unlike Wolverine, he doesn’t use his immortality to smoke or drink without consequence.
The most transgressive thing he injests are the festive holiday treats that beastfolk make as religious offerings for the Silver Wolf... which would be outrageous to anyone who doesn’t realize he IS the Silver Wolf, and eating those treats is the only way that he allowed beastfolk to pay him back for his protection.
And he doesn’t even make a show of eating those treats in front of other beastfolk.