A third-party panel of lawyers has effectively labeled Mizuho Bank's inaction on its loans to organized crime as a failure of governance — a grave problem that haunts the megabank more than a decade after its creation through the merger of three financial institutions.

While the Oct. 28 report compiled by the bank-appointed panel denied that Mizuho was engaged in an organized coverup or in collusion with yakuza groups, it pointed to the lack of communication among the bank's top management and their lax awareness of the seriousness of the mob-loan issue.

Mizuho's lesson from the latest scandal should be to establish a governance system befitting its size as one of Japan's top banks.