@MarbleCitadel
Actually, I don't think so. True that if you search for Tripone surname, you find a few there, but that doesn't sound like a name from someone with African roots. And Sammy definitly sounds more english than french, while Rufin sounds... well I don't know, but not french at all.
I actually don't see any countries where they would get such names, my guess is that the mangaka invented them.
My bet is that he wanted to give him some African background, and didn't knew which name he could use. If he was from USA or Brazil for example, it would have been easier to find a matching name.
Wild guess here, I'll bet he's Ghanean (if we ever know)