You may think of sushi bars today as hip, cool joints where you're expected to pay top dollar for food that doesn't quite fill you up, but sushi began as an early form of fast food. Think of it as the McDonald's hamburger of Edo Period Japan in the early 19th century. Hanaya Yohei invented what we know today as sushi as something regular people could eat by hand or with chopsticks at a roadside inn or in the theater.
The new dish was more popular than Coca-Cola. In the span of 20 years, thousands of sushi restaurants appeared throughout the country. To be fair, sushi at that point in history, bore only a faint resemblance to what we eat today. The pieces were about twice as big. Fish meat, in the era before refrigeration, was heavily marinated in soy sauce or vinegar or was heavily salted, so diners didn't dip it into any sauces.
Sushi gained an international reputation in the 20th century, when refrigeration allowed the dish to travel well. But, the evolution seems to be a common one. Yesterday's mass culture always becomes today's high culture. In another hundred years, McDonald's will be considered fine dining.
