Why can Japanese sushi be eaten cold?

Sushi is vinegar rice balls. Rice and vegetables are cooked in advance, and fresh fillings can be safely eaten after processing. Just use a small bamboo pole to apply the roasted laver first, then apply a layer of rice, put a row of stuffing, roll it into a cylindrical strip and cut it into sections. Because of the material, it can only be cold-formed, so it is cold food.