The history of sushi in Japan began around the 8th century. The original type of sushi was first developed in Southeast Asia as a means of preserving fish in fermented rice. In the Muromachi period, people began to eat the rice as well as the fish. During the Edo period, vinegar rather than lacto-fermentation was used to sour the rice. In modern times, it is an early form of fast food strongly associated with Japanese culture.
The original type of sushi,known today as narezushi, fermented sushi, was first developed in Southeast Asia and spread to south China before introduced to Japan sometime around the 8th century. Fish was salted and wrapped in fermented rice, a traditional lacto-fermented rice dish. Narezushi was made of this gutted fish stored in fermented rice for months at a time for preservation. The fermentation of the rice prevented the fish from spoiling. The fermented rice was discarded and fish was the only part consumed. This early type of sushi became an important source of protein for the Japanese.
The Japanese preferred to eat fish with rice, known as namanare or namanari,semi-fermented. During the Muromachi period namanare was the most popular type of sushi. Namanare was partly raw fish wrapped in rice, consumed fresh, before it changed flavor. This new way of consuming fish was no longer a form of preservation but rather a new dish in Japanese cuisine. During the Edo period, a third type of sushi was introduced, haya-zushi, fast sushi. Haya-zushi was assembled so that both rice and fish could be consumed at the same time, and the dish became unique to Japanese culture
It was the first time that rice was not being used for fermentation. Rice was now mixed with vinegar, with fish, vegetables and dried food stuff added. This type of sushi is still very popular today. Each region utilizes local flavors to produce a variety of sushi that has been passed down for many generations. Today the sushi dish internationally known as "sushi" (nigiri zushi; Kantō variety) is a fast food invented by Hanaya Yohei, 1799–1858, in today's Tokyo (Edo). People in Tokyo were living in haste even a hundred years ago. The nigiri zushi invented by Hanaya was not fermented and could be eaten using the fingers or chopsticks. It was an early form of fast food that could be eaten in public or in the theater.