I'm hooked on Tomi Sushi. First the Sushi is average but they have great lunch specials. They have the best tempura anywhere because they fry them like art.
Second you can't beat the prices for lunch.
I usually get Chicken or Beef with Tempura for $6.50. It comes with miso soup, rice, assorted tempura, chicken or beef and salad, little pickled sides and fruit.
It's sort of like Taiko in Irvine but better and cheaper.