The further you travel in Japan, the more you discover that each corner of the country has its own character and food traditions. Every region produces its own distinctive strains of rice, seafood products, miso, pickles and sake. And those differences are important: They're expressions of history, culture and local identity.
The easiest way to sample this diversity, if you're stuck in Tokyo, is to find your nearest antenna shop. From Hokkaido down to Okinawa, just about every prefecture has one to showcase local specialty foods while acting as de facto tourist information hubs.
Several of them also operate uncomplicated, affordable restaurants, mostly offering set meals of down-home regional signature dishes, with plenty of good sake and/or shōchū — exactly the kind of fare you expect to find at tourist sites or rural roadside rest stops.