My wife an I had lunch today at the Kona Grill in Fashion Square. First, if you are a sushi snob, this probably isn't the place for you. It's just not a 'fine food' restaurant. Rather it's a chain on the same level as P.F. Chang's or Cheesecake Factory. You know all of the food will be edible and on the tasty side but nothing particularly special.
The restaurant itself is quite pleasant and the sushi bar is pretty cool. Service was solid. Water and drinks refilled without needing to ask and our waitress was really nice. Unfortunately, the food wasn't at the level of the surroundings or the service. We ordered the Voodoo Roll and the Picasso role. Both were OK but I thought they sacrificed flavor for heat (and I love really hot foods). My wife disagreed and liked both rolls. I also ordered the spicy shrimp tempura. My advice...just don't. It was basically battered shrimp with a completely boring hot sauce. Rather than being light and airy like good tempura, this was just crunchy and a bit greasy.
My wife is an eel lover. She said that on a 1-5 scale, the eel was a 2. She thought it was rubbery and, in her words, just not right. The salmon sushi was just OK and she said the sushi rice was not particularly good. In addition, although the rolls were nicely plated, they didn't hold together well.
This would have merited thee stars but for the price. Over $70 for two mediocre rolls and some fried shrimp (yeah, some salmon and eel sushi too but only one order of eel and two orders of salmon) and no drinks is over the top. I can list a half dozen Japanese restaurants in the Valley with far better food and either better or similar prices.