The exacting art of edomae sushi and washoku, where a lifetime is spent mastering rice, knife, and the fifth taste at the source of a UNESCO-listed cuisine.
Sushi began as a way to keep fish, not to serve it: fish packed in rice to preserve it, first in Southeast Asia, possibly in the Mekong basin, long before it reached Japan. The craft a sushi chef practises was born in Edo, today’s Tokyo. Hanaya Yohei is believed to have invented nigiri, the hand-pressed form, around 1824, and edomae, fish from Edo Bay, is still a by-word for sushi done properly. In 2013 UNESCO inscribed washoku, the wider Japanese food culture, on its list of intangible heritage. Tokyo is where the craft is most alive today. In October 2018 the city moved its fish trade from Tsukiji to Toyosu, which opened as the largest wholesale fish market in the world.
What you can realistically reach: A short intensive teaches knife handling, rice (shari) and the logic of a washoku meal — enough to cook honestly at home. The traditional path to itamae mastery is measured in years, and an honest school says so.
There is a real difference between a school that teaches you and a good-looking website, and too much of the internet is the second kind. Four instruments do the work, and every one of them is visible on the page you are already on.
If a place dodges these, that's your answer. It costs you nothing to ask, and it tells you everything.
This is the short version. The full method is here — the six questions, in order, for any craft anywhere.