Sushi is one of the traditional Japanese cuisines. The main material is rice pieces seasoned with sushi vinegar and maintained at human body temperature. With fish, seafood, vegetables or eggs as ingredients, it tastes delicious and is very popular among Japanese people. Sushi has been recorded in the heian period Code "Yanxi Style" completed in 927 AD. Sushi at that time refers to a way to preserve fish. Rub salt on the fish, press it with heavy objects and let it ferment naturally. When it is sour, it can be eaten by wrapping it with crystal rice (it must be repeatedly rolled after being cooked and cooled), and it tastes very good. This method originated in Japan. According to Biography of Dongyi-Biography of Japan, Japanese people eat seafood, that is, sashimi (sashimi), which is wrapped with rice grains to form a kind of fast food.