[T]he Japanese have always loved fresh fish. But the waters close to Japan have not held many fish for decades.
So to feed the Japanese population, fishing boats got bigger and went farther than ever. The farther the fishermen went, the longer it took to bring in the fish. If the return trip took more than a few days, the fish were not fresh. The Japanese did not like the taste.
To solve this problem, fishing companies installed freezers on their boats. They would catch the fish and freeze them at sea. Freezers allowed the boats to go farther and stay longer. However, the Japanese could taste the difference between fresh and frozen and they did not like frozen fish.
The frozen fish brought a lower price. So fishing companies installed fish tanks. They would catch the fish and stuff them in the tanks. After a little thrashing around, the fish stopped moving. They were tired and dull, but alive. Unfortunately, the Japanese could still taste the difference. Because the fish did not move for days, they lost their fresh-fish taste.
The Japanese preferred the lively taste of fresh fish, not sluggish fish. So how did Japanese fishing companies solve this problem? How do they get fresh-tasting fish to Japan?
To keep the fish tasting fresh, the Japanese fishing companies still put the fish in the tanks. But now they add a small shark to each tank. The shark eats a few fish, but most of the fish arrive in a very lively state. Obviously, lively fish tastes fresh.
Have you ever realized that some of us are also living in a pond but most of the time tired and dull, so don't we a Shark in our life to keep us awake and moving?