We were lucky and were in Tokyo in time for the once a month buffet here. You definitely need reservations, there are 2 seatings and ours was packed. We made reservations 2 days prior.
Everyone gets there at the start time and you get an assigned seat. Then the host tells you where everything is (in Japanese, but it is not hard to figure out what he is saying). There were 2 kinds of soup, 2 curries, and about 15 different main dishes. There was also a dessert table. The 15 dishes included all kind of vegetables, pasta with fake meat, soba noodles, tofu omelet, pizza, and it was all tasty. There is a lot of food available and they keep replenishing it. It costs 3500 yen per person and includes basic drinks like tea.
The food is very good. There is a lot of variety in the flavors used.
It is pretty easy to find and the staff speaks limited english.Pros: Buffet available once a month, Delicious, Convenient location