With its drop to a one-week low on Wednesday, the dollar had fallen more than 2 yen from a peak of 90.18 yen hit right after the BOJ’s announcement on Tuesday.

“I think we will struggle to break 91, but I will still keep looking for us to trade above 90 in the short-term,” Bargmann said, referring to the outlook for the dollar versus the yen over the next week or so.

Yen bears have not given up, partly because BOJ Governor Masaaki Shirakawa, whose term ends in April, is seen likely to be replaced with a more dovish governor, who could then bring forward any easing.

(Read More: Japan PM Gets Inflation Goal; Next on List, A New BOJ Governor)

“Dollar/yen looks vulnerable in the short-term, although its longer-term outlook is still for an attack on 100 over the coming year,” said Steven Barrow, an analyst at Standard Bank.

Earlier on Thursday, the yen showed limited reaction to data showing a larger-than-expected Japanese trade deficit in December, and a record trade deficit for the whole of last year.

For 2012, Japan logged a record annual trade deficit of 6.927 trillion yen ($ 78.24 billion) as the sovereign debt crisis in the euro zone and a territorial row with China hurt exports, and the shutdown of nuclear power plants since the 2011 earthquake and tsunami pushed up energy imports.

Japan’s trade deficits have been a contributing factor to the bearish market sentiment against the yen, which has also been pressured by expectations for more drastic monetary stimulus from the BOJ.

The euro rose 0.6 percent against the yen to 118.75 yen, edging back in the direction of a 20-month high of 120.73 yen set on Friday.

Against the dollar, the euro held steady at $ 1.3316.

Markets Headlines