As Prime Minister Shinzo Abe prepares to reshuffle his Cabinet, the Tokyo buzz machine is obsessing about every official but for the one who matters most: Haruhiko Kuroda.

Yes, I know, the head of the Bank of Japan isn't part of Abe's administrative team. But, really, how independent is a central bank that has kept interest rates near, at or below, zero for almost two decades and wouldn't dare cross the prime minister? Even so, speculation is rampant that Abe's money man should get shunted aside to make room for an even more compliant BOJ governor when Kuroda's term ends in about eight months.

Here's a better idea: promote Kuroda to finance minister and move the current holder of that job, Taro Aso, to the BOJ. At the Ministry of Finance, where Kuroda served in the 1990s and early 2000s as a top international official, Kuroda could resurrect the reformist agenda Abe promised five years ago. All Aso would have to do at the BOJ is keep things on autopilot as a more intellectually curious man restructures Japan Inc.