A set of new rules unveiled by the Tokyo Stock Exchange requires all companies listed on its First and Second sections to have at least two independent outside directors on their board. The move is in line with the Abe administration's push to beef up corporate governance as a way of attracting more foreign investors.

The question is whether merely increasing the number of external directors will do the trick of enhancing transparency in corporate management and improving their profitability.

The TSE's new listing rules will come on the heels of a revision to the Company Law, to take effect in May, that calls on businesses to have at least one outside member on their board — a common practice among companies in Western economies. The TSE listing rules to be implemented in June do not punish companies that fail to comply, but will require them to explain why in their annual corporate governance report to the TSE.