Investing.com - The yen surged almost 3% against both the dollar and the euro after the BoJ held off stimulus.
Tokyo's Nikkei slumped 3.6% by the close and the FTSEurofirst 300 dropped 0.6%.
The New Zealand dollar jumped 2.5% after the central bank kept interest rates on hold.
Oil prices held near 2016 high and have now surged 65% since mid-January.