I ordered the Tempura Seiro Soba (天せいろそば) and it was a bit pricey at 1750 yen but it tasted great.
What I really liked about the restaurant though (besides the food), was the atmosphere of the place.
It had a bunch of really awesome art hanging on the walls that was reminiscent of Edo Period art and I'm a pretty big fan of that so it was really enjoyable.
The inside of the building was grey but it was very stylish. I'm not sure what the walls were made of, but it seemed to be some sort of granite and the coloring of the seats was also in a similar fashion but very tasteful.
I definitely want to go back here again and try some more of their dishes!
It's pretty close to Okachimachi Station so it's pretty easy to drop in for lunch.