Haruhiko Kuroda changed Japan in crucial ways during his decade atop the country’s central bank.

His successor will find it hard to undo the legacy, assuming he even wants to. Kuroda was a revolutionary in the cause of reflating an economy that once was lauded for possessing a secret sauce to, briefly, challenge the U.S. for financial supremacy. Some of his innovations have stored up trouble for the future — and probably not just in Japan.

To truly appreciate the impact of Kuroda’s tenure, we need to travel back to late 2012 and early 2013. Shinzo Abe had just led the longtime ruling party back to government after three years in the wilderness. He sought a major shake-up: monetary, fiscal and regulatory.