Dude I think if Banzu was hired out from under them it'd have totally created tension between Dad-Souda and Banzu, so it'd actually be a pretty cool dynamic to work with? Kazuichi isn't the type to blame him, though, so they could either have awkwardness or be p. tight friends.

Kazuichi's gonna be around 19ish I think-- and I'm assuming Banzu's older, right? It's also possible Kazuichi would look up to him. It'd be pretty dang cool to get these guys working together on things.