It's hard finding great sushi for a reasonable price. My husbands works at a Thai restaurant in a small town. He knows how to make those Lv.100's . x3 Just don't buy packed in common markets. It's not designed to sit out in a fridge all day.
Some restaurants are not as good as others, which is quite a shame, but then again you won't know unless you try.
I am currently going through this process, as I will be working in another down for the next few months, so I need to get used to the surounding, surprisingly I found about 5 places to eat lunch on my way from the train station to the work-place.
I dont know wich asian restaurant you went to, but if the food was good, you should consider yourself lucky. Me and my friends made the mistake to eat at a chinese restaurant and went back to the hotel with stomach aching because the sushi was disgusting as well as the rest of the buffet.