I've never been to Japan, but here's what I think of when I think of it:

Trains, lots of trains and small, crowded alleyways with airconditioners sticking out at odd angles.

Really ugly postwar buildings that seems to clash with surrounding architecture, yet strangely finds some harmony with the surrounding countryside, usually by reshaping it; lots of restraining walls shaping the terrain for instance.

little ramen-yas and obachans with floppy white hats. Skilled touch typing on cell phones.

cats.

cicadas.

All those Isuzu trucks that have no nose.
Policemen with white helmets.

And of course:
NEETS, Otaku bunka, Akiba, Oden-in-a-can, meido, Gensokyo.