In Toronto, the Janpanese sushi stands are quite successful. Before you open your own, maybe it is a good idea to take a trip to Eaton Centre at downtown Toronto and Markville Mall in Markham. Most stands are owned by Koreans (they make better J-food then HK people in general) and have good business. I think you can use some business models for emulation.
Actually, from what I observe, most of sushi eaters (aside from oriental customers which in Toronto we have a lot) are working white females between the age of 18 - 40s. And the location of your stand is very important.
I think sushi stand will do better in a mall with a lot of business buildings around it or something like that. You know what I mean? Because if it is only in the food court of a shopping mall, many customers are not in a rush and they can have a salad at a Greek fast food restaurant and fried chickens from KFC.
But if it is in a busy business neighborhood, a lot of white collars don't have time to wait during lunch time. You can just take their money and give them a box of sushi (pre-made). You can also sell some exotic healthy drinks from East Asia e.g. honey ginseng tea and etc. A lot of women buy into that kind of beauty stuffs ... Just tell them after they drink it they will have oriental girl's skin ...
Hee hee I am a very lazy person, it's only 6:55pm and I want to take a nap...
Good luck!