Remember when FEd decided QE1, USD shrink against the YEN, but when BoJ decided to put its , it was the otherway around.
At the present, we do have FED's Tappering vs Boj decision to put an end to the . But BoJ push really hard the . where as FED's QE1+2+3 were more gradual as the tappering is at the present.
Technicaly speaking it appears that we are on an overbought level and therefore, there may be a technical correction on the dowside of the pair, in favor of YEN until 101.8 or 101.5 where there is a solid .
After reaching that technical level for a correction, USD may go again on the upside toward 104 or around.