Japan's flagship companies were once held in awe as fierce competitors that revolutionized the world's business practices with innovations like flexible manufacturing and managerial precepts such as kaizen, or continuous improvement.

These days, Japan Inc. is turning heads for a less exalted reason: A string of scandals that's destroyed shareholder value, enraged consumers and incurred the wrath of regulators.

Kobe Steel Ltd. raised fresh concern about the integrity of Japanese manufacturers after disclosing on Sunday that it falsified strength and durability data on aluminum used in products ranging from cars built by Toyota Motor Corp. to bullet trains made by Hitachi Ltd.