2.5 million pounds of fish pass through Tokyo's Tsukiji fish market every day on their way to the rest of Japan and Tuna Hell (tekka jigoku) is at the heart of this process.

Picture a huge concrete dock stretching out into Tokyo Bay. Lined up on this dock are thousands of pounds of fresh(ly frozen) fish. Numbers are painted on their scales to differentiate between them and flaps are cut into their flesh by their tails to expose the texture. Potential buyers wander the aisles between these fish with hooked poles to poke, prod and sample the merchandise.

Auctions that occur in Tuna Hell are surprisingly sedate and fast, probably because the buyers do this for a living. Ever seen a professional poker game? Notice how quiet it is? Tuna Hell is like that.

Sources: http://webjapanese.com/column/english/980715.html
"Tokyo Story," from Fraud, an essay collection by David Rakoff