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>>2
I might as well give my opinion too instead of just asking you about Nagoya.
All the things mentioned so far really require a basic, singular understanding of segments of our or any society. If this guy is like most Japanese, he already is somewhat acquainted with seeing and, in a limited fashion, reading English (advertising etc.). Neither asking for directions nor going to a restraint really require anything more than pointing to a proxy (map/menu), saying a name (Brooklyn Bridge/Whopper), and then being told a value to pay. Most traffic signs don't even have words on them. You'll essentially be teaching him more "advanced" ways to do things which honestly require little linguistic effort in the first place. I know he only wants to commit 30 days and he's digging his own grave, but I think a more thoughtful approach can at least put him on a foundation to learning "essential" English in that time frame. And I'm not saying the set phrases of "How do I get to..." and "How much is..." or the everyday scenarios in which they're utilized should be glazed over. Only that they constitute "basic" not "essential" English.
If this is his first time going to America, I would spend at least the first day getting him acquainted with what he can expect from the country itself or the people he'll be interacting with. It's not necessarily language training but giving him an idea what to expect and how to interpret it, instead of only how to interact with it through language, will not only put him at ease but help him utilize his speech more effectively. Talking about how someone might come up out of the blue and pat his back, ask him how his day is going and expect a response, spark up a conversation about his hobbies or his family, fake a laugh or smile that's meant to be returned, or get openly frustrated at him for disturbing a flow AND how to respond to it would be extremely beneficial. Spending a session on the appropriate situations and methods of handshaking or greetings might even help. Japan isn't all too different from the west in terms of how it's traffic is set up or how it's restaurants or shops operate. If he's an intelligent adult, he'll figure that out.