Sushi is not, as is generally thought, the raw fish that the Japanese and, through their influence, the gourmets of the entire world, eat. Sushi is actually the vinegar-mixed rice that is used to prepare Sushi. The raw fish itself is called Sashmi.
The Japanese have a long history of pickling rice and fish together. Pieces of raw fish would be mixed up with rice and covered up. This would then be stored for several months, sometimes even for an entire year, before it was deemed ready to it. This type of Sushi is called 'Nare-Sushi'. But a lot of people didn't have the patience to wait several months to eat their Sushi and so a new, more quickly fermented type called 'Nama-Nare Sushi' came into being. Then came the 'Edo-Mae Sushi', which was invented in the 17th Century by Matsumoto Yoshiichi, a Chef from the Tokyo Bay Area; Edo was the old name for Tokyo. He came up with the new recipe by adding vinegar to the rice. This not only make the preparation of Sushi quicker, it gave it a whole new, interesting taste.
The modern-day kind of Sushi was created by Hanaya Yohei, also of Edo, in the 19th Century. He did away with all the lengthy preparations and, by serving thin slices of raw fish with vinegared, salted rice to waiting customers, turned Sushi into a bite-sized Japanese Fast Food.
The difference in Sushi is more in the ingredients used than in the preparation methods. There are four main types of Sushi -
Nigiri Sushi - This is the simplest type of Sushi. It is just fish on top of rice, and sometimes the bite piece is held together with a dried seaweed called 'Nori'. A lot of times the Sashimi here is cooked.
Maki Sushi - This is a rolled type of Sushi. The rice and fish come rolled in small cylinders or cones of seaweed.
Oshi Sushi - This is a pressed type of Sushi. The rice and fish are mixed together in a mold and pressed hard to form a solid slab. Small squares from these are then cut off and served.
Chirashi Sushi - This is a scattered type of Sushi. Here a great many ingredients, all cut into tiny pieces, are scattered on top of the rice.
The Japanese follow a certain etiquette when eating Sushi. You can do the same. First of all take a look at the wide display of Sashmi that the Chef has and consult him in making your choice. Try Maguro and Hamachi (Tuna), Sake (Salmon), or Unagi (Eel) rather than the dangerous Fugu (Blowfish) for your first Sushi experience. If you don't know what to order, tell him 'Omakase Shimasu', which translates to 'Choose for me, please'. He'll probably be well-versed in English, but he might be impressed by your effort to learn Japanese.
After you sit down, you will be given a hot towel called 'Oshibori' to wipe your hands and face, and then offered a drink. Choose 'Sake', a type of Rice Wine, and drink it before your order arrives. Sake is never drunk while eating Sushi, but you can have Green Tea along with the meal. Sometimes Miso Soup is eaten before the Sushi.
Then when the Sushi arrives, take up your chopsticks and pick the raw fish. Dip it in the accompanying small dishes of Soy Sauce and a horseradish sauce called Wasabi and then eat. Watch the Wasabi though, it can be very hot and pungent, especially if you're not accustomed to it. Usually you also get thin slices of ginger to go with the Sashimi. The rice, please remember, is never to be chopsticked, but eaten with the hand. It's simple. Chop Sashmi, Chop Not Sushi.
And, oh yes, the finger bowl that's sent around - that's really for the fingers. Don't drink it. After you're done, smile and say, "Gochisoo sama deshita!" That means it was quite a feast. Then say, "Domo arigato," or "Thank you very much," and show your appreciation even more with "Oaiso kudasai". Which means "Bring me the bill, please." Well, there you are. Kampai!