Iwasa is a hidden gem in Tsukiji Fish Market. Owned by sushi brokers and manned by wonderful chefs, the omakase sushi set is out of the world and the wait is far less than that of Sushi Dai and Daiwa.
Really great tuna, naturally since they're right next to tsujiki. Went there at 6:30 am after watching the auction. A great alternative to daiwa, where the line is LONG
"Hidden gem" is thrown a lot but I don't know what else to call it. We got to the market at 9-ish, walked in, got a seat at the counter, ordered omakase and left with bellies and hearts full.