If you want a very special Japanese meal, then make sure you go to Sugiyama. This is truly a dining experience that you will remember for awhile. First, the chef goes to great lengths to create some very innovative dishes. And you really have to trust his judgment because you order different levels of meals (i.e. number of items) and the chef chooses the specifics. Fortunately, his reputation is well deserved and even the most exotic selections are delicious. There were definitely some things on my plate that I wouldn't have tried otherwise (i.e. crispy little crab that you eat whole). But don't let that scare you because anyone who likes sushi will be delighted. In fact, I strongly recommend you choose the menu item that gives the chef the greatest amount of leeway (i.e. chef selections for the night).
As for the atmosphere, it is a very classy, well designed restaurant. The interaction between chef and patrons is nice given that he prepares the food in full view and greets everyone who comes in...and he asks how your meal was as you leave. The service is impeccable although the English of our server led to a couple of funny exchanges. Expect something a little more traditional than some of the trendy Japanese restaurants that are popping up all over the place.
A few notes:
1. Leave plenty of time for your meal. The selections come one by one and the meal is meant to be enjoyed not scarfed down. We were there for around 2 1/2 hours for perspective.
2. Be prepared for a pricey meal. It is easily a $150 meal for two if you have any alcohol.
3. Try everything...some of the most bizarre items on the menu were the best things I had.