Outside Japan, some people think sushi simply means “raw fish.” In Japan, however, sushi and sashimi are clearly considered different foods.
The easiest way to understand the difference is to look at the rice.
Sushi is built around sushi rice—rice seasoned with vinegar. In nigiri sushi, fish or another topping is placed on top of the rice. In makizushi, the rice and fillings are rolled together, usually with seaweed. Chirashizushi looks different again, but sushi rice is still at its base.
This also means sushi does not have to contain raw fish. It can be made with grilled fish, cooked shrimp, egg, vegetables, and many other ingredients. Raw fish alone does not make something sushi.
Sashimi, on the other hand, is a dish of sliced seafood or other ingredients served on their own. It is commonly eaten with soy sauce and wasabi, but sushi rice is not part of the dish.
A sashimi set meal makes the distinction especially clear. Even if slices of sashimi are served next to a bowl of ordinary white rice, Japanese people would not consider that sushi. The rice and sashimi may be part of the same meal, but the sashimi is still sashimi.
The same tuna can therefore become two different dishes. Slices of tuna served by themselves are tuna sashimi. Put the tuna on sushi rice, and it becomes tuna nigiri sushi.
For Japanese people, saying “I ate sashimi” and saying “I ate sushi” normally mean two different things. Calling a platter of sashimi “sushi” would sound a little strange.
The difference between sushi and sashimi is not whether raw fish is present. Sushi is a dish built around vinegared rice, while sashimi is sliced seafood or other ingredients served and enjoyed on their own.
