But Japanese-Americans aren't the Exchange's only clients.

As young Japanese and Japanese-American customers sat gobbling up raw fish at one of the mall's two sushi bars Saturday, the atmosphere was riddled with subtle hints of American culture.

On the television screen hanging above cold salmon, squid and octopus, the North Carolina Tar-Heels were driving on the Virginia Cavaliers in one of the day's college football matchups.

"They almost always have a football or baseball game playing," said Mark W. Gailus '74, an Exchange regular and Somerville resident who was having lunch at the bar with his wife and son. "We usually come for the food-it's a nice change of pace," he said.

Gailus said that he never would have known about the Japanese enclave if he hadn't stumbled on it one day while doing other errands.

But while the Asian arcade may draw a relatively diverse group of clients, managers admit that is also a small group.

"We don't consider ourselves a destination," said Joe Roux, the Exchange's facility manager. "You either already know of us or you're from the neighborhood."

But Roux is quick to point out that the cluster of Japanese businesses is utterly unique.

"The only place that I could consider close to this is Chinatown," Roux said.

Indeed, while Japanese supermarkets may exist in Central and Union squares, nothing in New England parallels the mall's cultural concentration.

Roux also pointed out that the food at the Exchange is of a different quality than its competition.

"The food here is more traditional-it's all prepared in the building by hand," he said.

And according to Roux, such quality attracts a certain group of customers.

"I would say that our clientele is generally on the higher end of the income spectrum," he said.

Other described Exchange's clients in more practical terms.

"If you want to see the latest hot cars, just sit around this lot for a few hours," said a security guard who refused to give her name.