Japan's long-suffering savers have put up with virtually zero interest for years, but at least their bank accounts have remained free.
That may now change, as speculation mounts over the possible use of further monetary stimulus.
Lenders could begin imposing maintenance fees for retail deposit account holders if the Bank of Japan deepens negative interest rates from minus 0.1 percent, according to JPMorgan Chase & Co. analyst Rie Nishihara. A central bank board member also warned last month that banks may have to consider such a change.