The yen held near recent three-and-a-half-year highs against the dollar on Tuesday, supported by more signs of a solid economic recovery in Japan, but intervention fears kept investors on a cautious footing.
Analysts said that dealers were also reluctant to take positions ahead of big events later in the week including Japan's "tankan" survey of business sentiment on Thursday, and a policy meeting on the same day by the European Central Bank.
The market is also keenly awaiting non-farm payroll figures due on Friday, which are expected to show that US companies are finally hiring aggressively, raising expectations for a quicker end to the Federal Reserve's low-rates stance.
"We're looking for 150,000 on the payrolls and an ECB cut, and that would imply a dollar positive outcome. It's possible there'll be a little bit of a squeeze on dollar/yen, maybe to around 106," said Jake Moore, strategist at Barclays Capital in Tokyo.
US non-farm payrolls are expected to have risen by around 100,000 in March, compared to a disappointing figure of 21,000 in the previous month.
The dollar was around 105.60 yen flat from late US levels and not far from its low of around 105.16 yen hit last month.
Dealers also remained on the lookout for Japanese authorities amid speculation - rekindled by a British newspaper report on Monday - that Tokyo may scale back its yen-selling intervention.
The Japanese authorities intervened heavily in February to stop the dollar from dropping below 105 yen, a level they are seen as keen to support, at least until March 31 when Japan's big exporters close their books for the end of the fiscal year.
Finance Minister Sadakazu Tanigaki said once again on Tuesday that Japan's currency policy had not changed and that it would intervene if market rates strayed from fundamentals.
The euro, undermined recently by speculation that the ECB may cut rates to shore up a sluggish euro-zone economy, ticked up as some traders bought back the currency ahead of the ECB policy meeting on Thursday.
It was quoted at $1.2187 from around $1.2155 in late US trade.
Some analysts said the ECB would be patient.