is a Japanese dish of prepared , usually with some sugar and salt, accompanied by a variety of , such as seafood, often raw, and vegetables. Styles of sushi and its presentation vary widely, but the one key ingredient is "sushi rice," also referred to as , or . The inventor of modern sushi is believed to be Hanaya Yohei, who invented nigiri-zushi, a type of sushi most known today, in which seafood is placed on hand-pressed vinegared rice, around 1824 in the Edo period (1603–1867). It was the fast food of the chōnin class in the Edo period. Sushi is traditionally made with medium-grain white rice, though it can be prepared with brown rice or short-grain rice. It is very often prepared with seafood, such as squid, eel, yellowtail, salmon, tuna or imitation crab meat. Many types of sushi are vegetarian. It is often served with , wasabi, and soy sauce. Daikon radish or are popular garnishes for the dish. Sushi is sometimes confused with sashimi, a similar dish in Japanese cuisine that consists of thinly sliced raw fish or occasionally meat. History A dish known as , stored in fermented rice for possibly months at a time, has been cited as one of the early influences for the Japanese practice of applying rice on raw fish. The fish was fermented with rice vinegar, salt, and rice, after which the rice was discarded. The first mention of sushi is in a Chinese dictionary thought to be from the 4th Century, in this instance referring to salted fish that had been placed in cooked or steamed rice, which caused it to undergo a fermentation process. Fermentation methods following similar logic in other Asian rice cultures include (), (), , (), and . The lacto-fermentation of the rice prevents the fish from spoiling. When wet-field rice cultivation was introduced during the Yayoi period, lakes and rivers would flood during the rainy season, and fish would get caught in the rice paddy fields. Pickling was a way to preserve the excess fish and guarantee food for the following months, and became an important source of protein for Japanese consumers. The term sushi literally means "sour-tasting," as the overall dish has a sour and umami or savory taste. The term comes from an antiquated terminal-form conjugation, no longer used in other contexts, of the adjectival verb , resulting in the term . still