Here in Japan, they call the sushi chef as an itamae. It is not just easy to become a cook or an itamae. In becoming the chef, you have to have the skills that are needed. In Japan, there are certain rules that one has to follow also if he wants to be the chef. In the infographic, you could see the needed skills and also the training or experience that one must have so he can become a chef. Here is the infographic.
You can see the detailed explanation and enumeration of the required skills of learning to become a cook of the sushi. It is one of the best menus of Japanese cuisine and it really has the great importance to the people as part of the food intake. They could also have it in their homes but one could also taste the one which they have in restaurants. There is no required perfect step as a chef could be able to put his creativity into cooking and presenting the food.
That is what makes also japanese people in the good advantage as they take the trade like their own. They ensure that quality and standard is met and at a certain level. But it is not just in the strict sense as there is room to impart the own creativity, knowledge, experience and the love of the itamae or anyone that would cook any of the food, not just the sushi. So have fun on your food adventure.