TAKATSUKI, Japan — Savoring sizzling slices of beef, Shuji Shimoji doesn't care if the restaurant where he is dining is the only one in Japan to begin serving American beef since a ban was lifted last month.

"It's delicious," said a grinning Shimoji, 23, bringing the juicy beef strips to his lips with chopsticks. "I wouldn't be eating this if I were worried, would I?"

Zenshoku Co., which specializes in barbecue restaurants, began serving American beef at 57 of its outlets yesterday — the first restaurants to do so since the easing of Japan's ban on U.S. beef, imposed in 2003 due to mad cow concerns. Japan was once the top destination for U.S. beef, importing $1.4 billion worth a year.

Many Japanese are still worried about the safety of U.S. beef, which has yet to be sold at Japanese supermarkets — except for the nation's five Costco stores, run by the Japan unit of U.S. warehouse retailer Costco Wholesale Corp. Even Seiyu Ltd., the Japan unit of U.S. retail giant Wal-Mart Stores Inc., isn't selling American beef just yet.

But Zenshoku Chief Executive Shigemi Oishi says he's sure the new checks in place that followed talks between the U.S. and Japanese governments now ensure the beef imports are safe.

"Japanese are conformist and so if no one is eating it, then they don't eat it. But once people start eating it, then it will slowly catch on," Oishi said. "The fears about American beef are exaggerated."

The U.S. government repeatedly has said the beef is safe because of stringent checks. But such assurances have done little to allay the fears of Japanese consumers about mad cow disease, or bovine spongiform encephalopathy, a degenerative nerve disease in cattle.

A survey by Tokyo-based marketing researcher Intage earlier this month found that 54 percent of the respondents said they wouldn't buy American beef.

Zenshoku's Oishi said he decided to use U.S. beef after his company went to inspect American ranches. But the restaurant was making sure the origins of the beef were clearly labeled on the menu — U.S., Australia, Japan — and the plates the waiters brought filled with mounds of red beef slices from the U.S. even had tiny American flags on them.

Oishi denied he wasn't being out first as a publicity stunt, and acknowledged he may be even taking some risks in serving U.S. beef amid the mad cow fears.

Yasuhiko Imura, a Zenshoku manager, said some people prefer the taste of the less fatty American beef to Japanese beef and say they can eat American beef more often without worrying about their diet.