I ate once at what I thought was just a tempura place at the top of Opera City, whose name unfortunately I cannot remember. We got a set meal and it included some nice sashimi as a starter. I don't think it was Asahi Sushi but it was a pleasant and tasty meal, I'd say upscale rather than luxury.

Opera City is a 5 - 10 minute walk from the PHT. Go down the driveway from the entrance to the hotel, at the street turn left, turn left again at the street just past the firehouse, walk one block, turn right, and walk to the next major street (about 300 m). Cross the street and you are at Opera City.