According to this Nolo web page:
A creditor or the bankruptcy trustee might bring an adversary proceeding to challenge the dischargeability of a particular debt -- alleging that you incurred it through fraud.
Some of the 6,501,119,371 Japanese Yen debt owed to It's banks could have been questionable. There is a Swiss investigative firm, CCI, investigating Mizuho Bank's network of correspondent banks in Europe, that has alleged a pattern of bank fraud.