With shrinking prospects at home and the threat of further yen weakness, Japanese companies are rushing to buy overseas and seem willing to pay top dollar, as shown by Japan Post's $5 billion bid for Australia's Toll Holdings.

Over the long term, Japan's demographics give a bleak prognosis for domestic demand; the population has been falling for a decade and is projected to drop from 127 million to 87 million by 2060, 40 percent of whom will be over 65.