Nikkei sinks 0.6% to close at 9,057.26

as a strengthening yen dragged down the country’s vital export sector.

So, you use the strength of the Yen to import cheap materials and drop the prices to sell overseas.

A no brainer for most.

Investors outside japan are buying yen to invest as the country is rebuilt after the tsunami. That pushes up the price of the yen. In a way you could say that equities and bonds of new construction are competing with traditional exports in the market for foreign currency, pushing the price of foreign currency down.