Better get a reservation, they only have about 10-12 seats. Last time, I walked all the way from Asakusa station and I arrived 30 minutes early. The restaurant was empty but they stated that it was all booked up. In order for a guaranteed reservation, you will need to book through a 3rd party website (cost about $80 CAD per person to book and not including the food). Some people were lucky to show up without reservation. I end up taking to the ferry to Odaiba and eat instead lol