An outspoken regulator has unleashed an unusual tactic to shake up Japan's asset-management industry.

Nobuchika Mori, the head of the Financial Services Agency, has publicly criticized the country's money managers for what he sees as failing to offer products that suit their customers. In his eyes, that's getting in the way of one of the key missions of Abenomics: to encourage Japanese people to move more of their $8.4 trillion in cash and bank deposits into the stock market.

In an attempt to address this, Mori is starting a new tax-free investment program for individuals who want to put a small amount of cash into equities and bonds each month for their retirement. Only cheap funds suited to long-term investment are eligible, which ruled out 99 percent of those available as of March. For one of the few money managers whose funds meet the strict criteria, the program will be a game-changer.