Financial Services Agency - FSA
If you run a bank in the U.S., the main regulator you have to worry about is the Federal Reserve. Move your bank over to Japan, and then you'll have to deal with the Financial Services Agency.
The FSA is Japan's main governmental regulator for the financial sector. Unlike the U.S., where financial regulation is spread out over a few agencies, with the Fed looking over banks and the SEC overseeing the securities industry, these functions come from one agency in Japan. The FSA has responsibility for banking and securities, as well as the insurance sector.