More attention is being focused on Japan's monetary policy, given the changing economic environment at home and overseas.

The recovery is losing its steam, total outstanding government bonds have reached 770 trillion yen, and interest rates can't be raised without further straining state coffers and causing losses for holders of those bonds.

Record-high oil prices are raising inflationary concerns, while the Federal Reserve has raised U.S. interest rates six times since last year. Japan, meanwhile, has kept its so-called "zero interest rate" policy in place for 42 months.