The "Maguro (tuna) " has been assumed to be for food for a long time in Japan, tuna's bone has been excavated from the kitchen midden of Jomon Period. And at that time, tuna's reputation was not good because it was perishable over.
The tuna was a popular fish until before the war, and mostly the part of lean was eaten. As for "Toro" that was the part of fat, it was unpopular because it was very perishable. So the "Toro" had been entirely used for processed foods. But after the 1960's, by the advancement of the cryopreservation technology, "Toro" has been valued highly as a raw food.
In statistics in 1995, the tuna haul in the world was 1.91 million tons. And Japan consumes 710,000t among those, and is eating 600,000t as sashimi and sushi.
Thus, the tuna is irreplaceable existence for the Japanese. Especially, the reason why Japanese loves "Maguro" is that it's terribly delicious.
