@dragonfruit:
Thats a bit odd. With the disaster happening in Japan right now, shouldnt the JPY be losing steam? Do we have any experts here?
Nop, Many US investors invested in JPY because they saw more "security" in that currency with the growth of Japan and the crisis with the USD.
Now that Japan have been hit by the tragedies, there is a oil concern as well as a concern among all the investors that relied on Japan. Despite all this the funny thing is that when there is Chaos in the world , the USD goes down, when there is Chaos in the US, the USD goes down and when there is Chaos in the US , many exporter countries currencies goes high. Not to mention that investors always think in riskier ways and they believe that after the earthquake and tsunami, many companies that suffered damages, will then buy their assests back.
But if you wish to have more concrete info:
http://www.businessinsider.com/after-earthquake-the-yen-explodes-higher-as-everyone-scrambles-for-cash-2011-3