Originally Posted by
tearex
Let's be more specific.
Sushi Ginza Iwa and Sushi Iwa 815 are two separate restaurants. And to further add to the confusion, there is Iwa Hanare.
od_sf is talking about Sushi Iwa 815.
TWA884 Is talking about Sushi Ginza Iwa.
I myself have been to Sushi Ginza Iwa and can recommend it for lunch, though it is not my favorite experience. I prefer a longer meal at Sushi Shin in Nishiazabu (about 12 min taxi ride from Tokyo Station), if you can do the dinner, just due to the interaction and watching the preparation.
OP, unfortunately many top-end sushi places are closed Mondays.
Just to clarify, both Ginza Iwa and Gina Iwa 815 are owned by chef Iwa-san. These days I recommend the 815 location because that is were Iwa-san works, the original location is now operated by assistants.
Of course, there are shops in Tokyo with better sushi than Iwa, but Iwa-san's restaurant is a great introduction to high end Tokyo sushi for a first time visitor. Easy location in Ginza, restaurant is very used to foreign guests, and the sushi itself (when Iwa-san prepares it rather than an assistant) is very seasonal, very balanced, and with delicious, flavorful shari. And also, Iwa is considerably easier to book on short notice than the very top places.
Even if Shin happened to have an open seat, I'm not sure that it would make sense to send someone with so little time in town to a very residential area in
Nishiazabu, especially if they want to take public transport. The nearest station to Shin is either the Hiroo or Roppongi station, and both are a good 15 to 20 minute walk away.