Dressed in a light-gray suit with her hair pulled back tightly into a bun, McDonald's Holdings Co. (Japan) Chief Executive Officer Sarah Casanova walked stiffly into a news conference on Feb. 5 and addressed a throng of reporters.

"I would like to sincerely apologize, once again, for all of the great anxiety and concern that the recent reports of food-related foreign objects have caused our customers," Casanova said, before joining her Japanese colleagues in a deep five-second bow.

The prostration, however, did little to settle the ire of increasingly suspicious customers across the country.