I'm an American who's spent a good portion of the last four years road-tripping around 45 of Japan's 47 prefectures. AMA
I'm still short Aomori-ken and Okinawa. All the rest of the country I've seen at great length, and have stayed in a variety of hotels, from capsules to 1000-year old ryokan temples, have bathed in 67 hot spring baths. I've been able to take part in weddings, funerals, festivals, and office drinking parties. At this point, I think I've done just about all there is.
I'm not sure what kind of proof would suffice here, but I'll try to accommodate any requests.
[Edit: Part One of my albums, more coming later. Some of these pictures refer to questions answered in the AMA)
[Edit 2: holy god, suddenly, a deluge of questions. I'm gonna go get some dinner. Later tonight, I'll be back to answer as many as humanly possible. Thanks for the response!]
[Edit 3: well, this thing blew up faster than I expected. It's about to be bedtime- but if anyone's still got questions, I'll try to answer them tomorrow! Cheers, all]