Sushi has always been two kinds, and sushi is a traditional food in Japan. Sushi in ancient Japan was salted fish marinated with salt and rice, which later evolved into sushi today. "Sushi" was written as "すし" in ancient Japan, which originally meant salted fish.

Japan (Japanese: にほんこく; English: Japan) is the abbreviation of "Japan", and its country name means "the country of sunrise", located in East Asia. Its territory consists of four big islands, Hokkaido, Honshu, Shikoku and Kyushu, and more than 6,800 small islands, with a total area of 378,000 square kilometers. The main ethnic group is the Japanese-speaking Yamato ethnic group, with a total population of about 1.26 billion. The three major metropolitan areas in Japan are Tokyo Metropolitan Area, Osaka Metropolitan Area and Nagoya Metropolitan Area.