The history of sushi began with paddy fields, where fish was fermented with vinegar, salt and rice, after which the rice was discarded. The earliest form of the dish, today referred to as narezushi, was created in Japan around the Yayoi period (early Neolithic–early Iron Age). In the Muromachi period (1336–1573), people began to eat the rice as well as the fish.During the Edo period (1603–1867), vinegar rather than fermented rice began to be used. The dish has become a form of food strongly associated with Japanese culture.
The earliest form of sushi, a dish today known as narezushi, originated in Southeast Asia where it was made to preserve freshwater fish, possibly in the Mekong River basin, which is now Laos, Cambodia, and Thailand, and in the Irrawaddy River basin, which is now Myanmar. Narezushi in ancient China is first documented around the 4th century, when the Han Chinese migrated south[broken anchor] to adopt this food from the Baiyue (the original non-Han inhabitants of southern China in the Neolithic, related to modern Southeast Asians).