There is a Denny's (www.dennys.jp/dny/index.html) about a block from Tsukiji, open 24 hours. A popular spot to hang your head all night with a cold cup of coffee in front of you.
...or here. Look for the "D" in the middle of the map:
Tsukiji Market is the kitchen of Tokyo. And its area is the largest among Asia.
The market starts at 3am when the discharged fish are lined up before the auction that start at 5am.
Then the auctioned fish are sold through the brokers to the resellers.
Fondest memory: VTer Sharrie made me taking her to the market which was just exciting experience for me, too!
Favorite thing: Get your tired ass out of bed and go to the HUGE Tokyo fish market before 7 in the morning! You will not regret it! Fish and seafood you didn't think one could eat, in all colours and shapes. And most of it is still alive when it is being bought. It doesn't get any fresher. The health inspector keeps an eye on it all. HUGE and deep red tuna, octopussy in seven different colours or more, strange snails. Most fishermen are happy and proud to pose with their catch. BRING YOUR CAMERA!