The Tsukiji Fish Market is a must for all who visit Tokyo. How can I put it? I don't like sushi... but I loved the sushi there. This is what sushi should taste like everywhere. No bland taste there; the fish is so fresh you'd think it'll whack you with its tail.
The restaurant opens at 7am and closes when there's no more fresh fish (10am is sometimes too late)
Uni (Sea Urchin)