Sushi was introduced into Japan from China around the 7th century. The first document concerning sushi was found in an old law document, Taiho-Ritsuryo (701/718). That referred abalone and mussel in Nare-zushi type.
Originally, sushi was very simple, incorporating raw fish, pressed between layers of salt, and weighted down with rocks to press it flat. After about a month, this process would make fermented fish, which was necessary to keep food over winter.
Around the 1500’s, refrigeration became a part of everyday culture so using semi raw seafood, Nama-nare was invented.
These days, sushi restaurants around the world have added a fusion of nationalities to this traditional dish. For example, at O-Sushi they create inside out rolls, and use some Mediterranean style ingredients.
There are two distinct styles of preparation.
Kansai Style – mixing seasoned rice with other ingredients. Then displayed into decorative and delicious creations.
Edo Style – A select piece of seafood or shellfish on a small pad of seasoned rice (technically called nigirizushi).