(Funa•Zushi, preserved fermented fish sushi)
Originally developed in Southeast Asia as a way to preserve fish in salt and rice, the original form of what we now call sushi was introduced to Japan in China around the 8th century. The first sighting of sushi appeared in the book in 718. Thought called sushi, it was far different from the one we see at the restaurant.
The fish was marinated in salt and rice for a few months. After fragmentation, only fish was consumed, and the rice was discarded. It was more like fish pickles. In some parts of China and the northern part of Thai, they are still making this type of “sushi” or preserved fish.
During the 9th century Japan, fish, shellfish, deer, hog meat were used to make preserved sushi. Because of the lengthy process of making this type of sushi, only served as a gift to the riches, high ranked officials, and lords.
Around 1700, the type of Sushi known as “Oshizushi”(pressed sushi) became popular. Oshizushi was made by applying vinegar to cooked rice, placing slices of fish on top and press it with some weight. A doctor named Ryoho Matsumoto is said to be the one to come up with the idea of adding vinegar to the rice.
The form of Sushi, Nigiri, and Rolls we know now were developed in Tokyo (called as "Edo" around the 19th century. ) It is said that a man named Hanaya Yohei is the inventor of Edo style sushi. To prevent spoilage, Hanaya either slightly cooked or marinated the fish in soy sauce and vinegar.