The dollar rose as high as 103.92 yen, taking its gains over the past month to about 4.6 percent. It also rose to its highest level against the Australian dollar in more than three months at about 0.8910.
(Read more: Get ready, here it comes: A December taper)
"The move in dollar/yen has certainly entered levels that are interesting," said Emma Lawson, a senior currency strategist at National Australia Bank. "Most people have moved towards expectations for a December or January taper and the yen is standing out as the currency to short."