Kohada（Gizzard shad） is one of the popular sushi ingredients as well as maguro. Firstable, sushi chef check the size and fat content of fish. After that, it is salted and set aside for a while and then vinegared. All the skillfulness of sushi chef lives on this process. With each bite on soft flesh, a flavor and tastiness of blue-skinned fish spread in the mouth. However, when it is baked it emits a strange smell and boiling it leaves small, bothersome bones, which means the only way to eat it is marinating in vinegar and serve it as sushi.