One of my favorite restaurants in Tokyo is Nihonbashi Yukari. It is just a coincidence that it is called Yukari. It is not a coincidence that I worked at Takashimaya in Nihonbashi, just a few blocks from this oasis. Nihonbashi Yukari is a kaiseki restaurant serving seasonal cuisine. Chef Nonaga was the 2002 Iron Chef Winner, you can see the trophy when you walk into the restaurant.
If you are going for lunch, call ahead and order the Yukari Bento box. (3,675 JPY last time I had it, or about $35 USD.) It is a gorgeous presentation including tempura, sashimi, and usually something simmered and grilled.
Dinner here is reasonable for the several courses. I believe it starts around 10,000 JPY or about $100 USD. Ask to sit at the counter so that you can watch Chef Nonaga behind the counter as he works with the seafood for sashimi. The hot dishes are prepared by his team in the kitchen.
If you go, tell him New York Yukari sent you there.
Chuo-ku, Nihonbashi 3-2-14
closest station is Tokyo station’s Yaesu guchi (exit) or Nihonbashi.