The acronym NISA has a checkered image in Japan. To most people it stands for Nuclear and Industrial Safety Agency, the now discredited government organ that did such an ineffectual job of policing nuclear power plants prior to the Fukushima accident of March 2011. On Jan. 1, 2014, the acronym will take on a different meaning as the Japan (Nippon) equivalent of the U.K.'s Individual Savings Account system, under which individual investors in stocks or mutual funds will not have to pay taxes on dividends and capital gains. It sounds simple and irresistible, but according to Tokyo Shimbun it may prove to be as resistible as that other more toxic NISA.

At present, dividends and capital gains are taxed at a flat rate of 10 percent on personal income as part of a government incentive program to boost stock investment that will end this year. Originally, the taxation rate was going to return to 20 percent, the rate levied on regular savings accounts, which is what the finace ministry wants. However, the Financial Services Agency (FSA) thinks that more average people should be encouraged to invest in stocks and helped pass the NISA law, which was modeled after Britain's.

On the surface, the system seems easy. Anyone 20 years of age or older can open a NISA account with a financial institution, but is limited to only one, and for four years the individual cannot switch his or her account to another institution. The account holder can put up to ¥1 million a year into the account for five years, which means the maximum amount of non-taxable investment at any given time is ¥5 million. The tax-free system itself is limited to ten years, meaning no investments in NISA can be made after 2023.