I think they're both fucking with each other, and they both know it. It's the equivalent of a black guy pointedly using street slang with a white guy he doesn't

I think they're both fucking with each other, and they both know it. It's the equivalent of a black guy pointedly using street slang with a white guy he doesn't like. The sushi chef is the only one who doesn't realize exactly what's going on. Or maybe he does and he's playing along to have some fun at both their expenses. (Come to think, the chef is doing the same thing, isn't he? He can make himself understood in English when he wants to--"He say you under arrest, Mr. Deckard"--but he does business in Japanese, even when the customer is speaking English.)