The real Japan is actually hidden at the bottom of the Mariana trench. It was taken there for safekeeping just before the allied occupation.

The Japan that we see "on the surface" in any part of Japan these days is basically a movie set and permanently hired cast that was created for the film "Sayonara." Tokyo got a refit for the movie "Bladerunner." Nagoya is about to take on a London-theme so that they can shoot the next Bridget Jones movie there.