Where: JapanThe satsuma is a seedless Japanese citrus fruit. The flavor is virtually identical to a tangerine. It's very easy to peel, though finding them fresh in the Midwest isn't all that common.
Where: Japan
Sometimes known as asian pear, japanese pear, and apple pear, nashi is one of those "best of both worlds" proposals. After all, it's not the flavor of the pear itself that has set it beneath the apple, but the texture being slightly too soft and the shape altogether less pleasing.
"Curry", despite its origins in India, has manifestations in every country. Perhaps especially unique is Japanese curry, or curry rice as it is uaully known, as it's always served with rice.
Okonomiyaki is a common Japanese street food, sometimes called "Japanese pizza", although the description is misleading at best. While similarly customizeable, it's more of a savory pancakes, full of onions and cabbage, topped with okonomiyaki sauce.
Oden is truely unique. It's a thin soup, based around primarily different forms of what is known as "fishcake" available at virtually every Asian grocery store.
Miso soup: if you've ever gone out for sushi you've probably had it. You might have thought it was good. Well think again: restaurant miso is a fraction as good as you can make it at home, with barely more work than it takes to heat up some Cambell's soup.

Chestnuts have become a seasonal rarity in America, thanks to the chestnut blight that nearly exterminated them a century before.
Natto