Only a small sign in Japanese indicates the location of this extraordinary restaurant that serves only sushi and sashimi. Bypass the tables, sit at the sushi bar, and put yourself in the hands of Toshihiro Uezu, the owner and chef. Uezu imports hard-to-find fish directly from Japan, and on a typical night he will offer several different types of tuna, the prices of which vary according to the degree of fattiness and the size of the fish from which they are cut. The most quietly attentive service staff in the city completes the wildly expensive experience. Reservations essential. Subway: 4, 5, 6, 7 to 42nd St.-Grand Central.