The greenback, which rose 0.6% against the yen in the previous session, had failed to meaningfully recoup its 3.8% slump following Tuesday's news.
"The BOJ opened the door, obviously, for further unwinding of its super-loose policies," said Sean Callow, a senior currency strategist at Westpac.
Against the euro , the yen steadied at 140.27, while trading at 159.73 per pound .
Sterling rose 0.14% against the dollar to $1.2102, after having slid 0.85% overnight.
"In a world where risk sentiment is still very fragile, currencies whose countries have a twin deficit are at risk compared to others."