My very quick judgment is that “buy Japan” has been contrarian mantra issued to so many people that it now is conventional wisdom.
There is always opportunity to invest in companies that are in the middle of massive public scandals (e.g. BP), but whether such opportunities become a good value is whether people massively misjudge expectations.
In the case of BP, it was a political execution that translated into a disproportionate hit on the share price. In the case of “Japan”, it is very difficult to make the same judgment.
Hence, I’m keeping my eyeballs elsewhere.