Safe deposit boxes, expected to be secure, have become the center of a shocking scandal in Japan: a bank employee had been steeling large amounts of money and valuables from customers over several years. This incident strikes at the heart of the banking industry, which relies on trust.

A former employee in his 40s at MUFG Bank Ltd., Japan's largest megabank, stole valuables from customer safe deposit boxes at two Tokyo branches over 4 1/2 years, starting in April 2020. So far, about 60 victims have been identified, with losses totaling tens of billions of yen (several hundreds of millions of dollars).

Safe deposit boxes are designed to require two keys to open -- one held by the customer and the other by the bank. However, banks also keep spare keys in case a customer loses theirs. This system was abused to carry out the thefts.

The thefts were possible because of sloppy management practices. The former employee was solely responsible for managing safe deposit boxes at the branches concerned, apparently allowing him to use the spare keys without raising suspicion among colleagues.

Routine inspections, conducted every six months, were reduced to a formality. Spare keys were stored in envelopes labeled for each customer, but inspections only counted the envelopes and didn't check for signs of tampering. The thefts weren't uncovered until late October this year, when a customer noticed something was wrong and reported it.

To prevent this from happening again, MUFG Bank says it plans to centralize the management of spare keys at three national headquarters offices. While it is only natural that the bank takes full responsibility for compensating the victims and ensuring such incidents don't happen again, it's also important that this issue isn't dismissed as simply the wrongdoing of one individual.

MUFG Bank President Junichi Hanzawa only held a press conference in mid-December, about a month and a half after the issue came to light. "I recognize that this case shakes the foundations of customer trust and credibility, which are the core of banking," he said. However, the delayed response suggests a lack of urgency in addressing the problem.

This isn't the first time the bank has faced criticism. Recently, it was revealed that customer information had been shared with its securities subsidiary without consent. Unless the responsibilities of corporate managers are clarified, the bank will struggle to regain customer trust.

This incident isn't an isolated case. In another financial industry scandal, a former employee of Nomura Securities Co., Japan's largest brokerage firm, was charged with crimes including attempted murder-robbery after allegedly stealing a large sum of cash from a customer's home.

The Japanese government is promoting an "asset management nation" policy, encouraging citizens to invest. However, unless banks and securities firms address their systemic problems, it will be impossible for the financial sector to create an environment in which people can safely entrust their money to them.