Thanks to everyone for the prompt replies to my earlier post and here's how it went.
Dinner at Fujisan was not so bad thanks to the dire warnings and resulting low expectations. They actually had some interesting specials for appetizers, and the execution of them was not so bad. I had a white tuna sashimi which was not comparable to what I've had in LA, but it was fine and it is the first place I'd seen it on the east coast - maybe you have it in NYC all the time, but I haven't found it in DC. Also a yuba-skin steamed dumpling that was fine. The main dishes I had were broiled eel which was desperately mediocre, and my friend's pork katsu. Which was fine, it's a good choice for a place that isn't so great because it's not a terribly sophisticated dish. They were very nice to my friend's kids who were the reason we HAD to go there. It could have been a lot more horrible.
The next night we went to Gingko Leaf, where I had been once before, and I am sorry to report it was not quite as exquisite as the first time. I had the chirashi sushi and two of the pieces of fish had either skin or gristle that was really hard to chew. In retrospect I probably should have said something to them, but we were so engrossed in conversation that I didn't think of it. I would go back, though.
Ambassador Liquors in Manhattan definitely is the place to go for sake. Tragically they were out of the particular thing I wanted, and they said they could have ordered it and gotten it in one day - it was stupid that I didn't call them when I got into town. But now I know to do it next time. They have a huge selection and the sake guy is really nice and enthusiastic and helped me pick some good substitutes. They also have a great bulldog called Phoebe. It was a very pleasant experience.
The other place we ate, although this is also off the Outer Boroughs topic, was Soba-ya on 9th st in Manhattan, which I try to go to every time I am in town. If you are into Japanese and haven't been there I recommend it. And try the goma (black sesame) ice cream for dessert.
Thanks to everyone for the help.