The price at about 80 to 90, is where it should be longer term, where it was over 20 years, that would make them fairly competitive, and may mitigate low profits of their multinationals.
China has done this for years under a monetarist system, and that is unfair, including the subsidy of land, energy, and labor.
The entire region is hypercompetitive and the Japanese government realizes after years of waiting that this is a one way street, and it has very little to lose.
I think you will see signs of the currency drop easing once it dips below 90, or maybe as low as 60.
This is the only way out now for Japan, and if it causes their institutions and people to spend a significant portion of money outside of Japan, that would be good for them in the long run, however if the YEN collapses, it could create havoc.
There is a natural value to the YEN, they may also be doing other things to get out of this, we shall see, its still very early.
Hence its like a dagger very focused and powerful, the Japanese sure don't waste time when they see an opportunity.
So I hope and expect then to FALL to about 70-90 range, this should occur by the summer or earlier.
You will probably see other major currencies trying to do that, but the YEN is a less used currency than the USD, and it will probably help them more than hinder them. Its worth a try at this stage as the rest of the world has already started.