Guests ask often enough that it is worth writing down. This is not a best-of list. It is where Hiroshi eats when he has two days and no obligations, which is a different and more useful thing.
The rule for all of it: go at lunch. The same kitchens at half the price, and you will get a seat.
Sit at the counter, order the course, and do not ask for sauce with the first three pieces. Salt only. If the shrimp head arrives separately and still crackling, you are in the right place.
Look for a shop that closes when the buckwheat runs out rather than at a fixed hour. Order seiro, cold, and drink the soba-yu at the end — the cloudy cooking water they bring in a lacquer pot. It is not an afterthought; it is the second half of the dish.
The wait is the point. A proper unagi house grills to order and will tell you forty minutes, and the forty minutes is not negotiable or reducible. Order the plain grill rather than the rice bowl at least once.
Not in Ginza. Stay one district out, in Ningyocho or Kayabacho, where the buildings are lower and the coffee shops open at six. You will walk into Ginza in twenty minutes and you will eat better on the way.
Nine names went with this letter to the people who asked. Ask Yuki at the counter and she will write them down for you.