Which country is famous for sushi?

Japan, though sushi did not begin as a delicacy or even as a way of eating fish fresh. It started as narezushi, a preservation method probably from Southeast Asia: fish packed in fermenting rice, which kept it edible for months. The rice was thrown away and only the fish was eaten - the opposite of the modern dish.

What people now recognise is street food from Edo, modern Tokyo, in the early nineteenth century. Vinegared rice mimicked the sourness of fermentation without the wait, a slice of fresh fish went on top, and it was sold from stalls to be eaten by hand in a couple of bites. It was fast food, and the pieces were considerably larger than today's.

Refrigeration changed everything, and so did marketing. Raw tuna was low-status and often discarded as cat food into the twentieth century; its rise to the most prized fish on the counter came with freezing technology and, in the 1970s, with Japan Airlines filling empty cargo holds on return flights from Canada with Atlantic bluefin that North Americans did not want. Global demand followed, and bluefin populations have been in serious trouble ever since.