Sushi began one century ago in Japan as a method of preserving fish. It is told that the origins of sushi came form countries of Southeastern Asia. Cleaned, raw fish were pressed between layers of salt and weighted with a stone. After a few weeks, the stone was removed and replaced with a light cover, and a few months after that, the fermented fish and rice were considered ready to eat. Some restaurants in Tokyo still serve this original style of sushi, called narezushi made with freshwater carp. Its flavor is so strong that it obscures the fish's identity altogether, and narezushi is something of an acquired taste.

It wasn't until the 1900's that a clever chef named Yohei decided to forego the fermentation and serve sushi in something resembling its present form. It became very popular and two distinct styles emerged Kansai style, from the city of Osaka in the Kansai region, and Edo style, from Tokyo, which was then called Edo. Osaka has always been the commercial capital of Japan, and the rice merchants there developed sushi that consisted primarily of seasoned rice mixed with other ingredients and formed into decorative, edible packages. Tokyo, located on a bay then rich with fish and shellfish, produced nigirizushi, featuring a select bit of seafood on a small pad of seasoned rice. Although the ornamental sushi of the Kansai region is still very popular, it is nigirizushi that foreigners are familiar with.

Or

For hundreds of years the Japanese used to preserve their fish with salt and then press it in layers until the fish had fermented. In the early 1800's a Japanese entrepreneur decided put slices of raw seafood on pads of rice. This merge beginning started a new taste sensation and in no time became a major success throughout Japan. This culinary specialty eventually caught on in the Western world and is recognized as being prepared in the Edo tradition - formed by hand.
Many years of training and preparation has led to the development of culinary experts known as Sushi Chefs. These individuals were traditionally trained within strict apprenticeship programs while under the watchful eye of a Master chef. Upon graduation, the Sushi chef may hold an honored position and earn the respect and admiration of his/her peers. Not only does a sushi chef make the food look appetizing, but they are involved in every detail of the preparation... not to mention haggling with the fisherman for the freshest catch, preparing the many different types of Sushi, conversing with the customers and 'putting on a show'.