The yen gained ground following the policy shift amid skepticism over whether it will be enough to spur inflation.
USD/JPY was down 0.82% to 100.86, the lowest since August 26.
The yen was also higher against the euro, with EUR/JPY falling 0.9% to 112.37.
The U.S. dollar index, which measures the greenback’s strength against a trade-weighted basket of six major currencies, slid 0.18% to 95.81