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.