Japan is home to some of the finest cuisine in the world. There are famously more Michelin stars awarded to restaurants in Tokyo than to those in Paris (much to the consternation of the French). If I'm honest, I have to say I have a little sympathy with the French here, there is a feeling that some of the awards relate to the "X-Factor" of rare and exotic dishes but when it's you daily dining, it's harder to appreciate this characteristic. That said, the daily dining is typically outstanding.
Interestingly, it is so much a matter of daily intake that Japanese people themselves will often not distinguish between types of food and just say "we had Japanese for dinner last night". Even the word for "food", gohan, is shared with the word for rice, the staple being that ingrained into the culture. And it's only when you arrive in Japan you realise there are actually different types of rice, the sticky local variety and the non-stick Thai version are good examples of this.
But the subject will often arise as to what is the difference between sushi and sashimi? And it all comes down to a question of rice. Well, Japanese rice. Never try making sushi with Thai rice. It's an instant sashimi maker as the grains fall away and you're left with just the fish. So sushi is the delicacy of rice with thinly sliced raw fish and sashimi is the slices of fish on their own. But if you want to try sushi varieties and impress the locals, try a little uni, the interior mulch of the sea-urchin. You'll get a merit badge for that one. And if you want to show off with sashimi, ask for a rare plate of basashi. Be warned though, that's delicate slices of raw horse to you and me.