Narezushi is thousands of years old and traces its roots back to the rice fields of China, where the method of curing in salt and fermenting the freshwater fish that lived in the paddies was developed to give the seasonal catch a long shelf life. It is believed to have arrived in Japan at the country's ancient capital of Nara sometime in the 8th Century. For the next 1,000 years, until it evolved in the 18th Century into the slices-of-raw-seafood-draped-over-mounds-of-rice dish we know today, narezushi was a commonly consumed, nourishing and tasty source of protein. People would eat a few pieces of it with the fermented rice. They'd put a slice of it in hot water to make a medicinal tea. And they enjoyed it as a delicacy with sake at the tables of aristocratic and samurai families.