And who does the BOJ fool?

Bloomberg talking Japanese helicopters: Japanese Prime Minister Shinzo Abe's economic strategy relies on a weak yen to fuel exports, boost profits and end deflation, but the currency hasn't been cooperating.
Not even sub-zero interest rates have helped weaken the yen. The Bank of Japan (BoJ) in January imposed a negative rate of minus 0.1 percent on some reserves, and the yen is still up 18 percent against the dollar since the start of the year.
Even though Japan's unemployment rate of 3 percent is the lowest in over two decades, pessimistic employers aren't handing out significant raises, according to Daiwa Capital Markets economists Emily Nicol and Chris Scicluna. The Japanese economy “continues to do little more than move sideways,” they wrote in a report published Sept. 2.
That's putting pressure on Haruhiko Kuroda, the governor of the Bank of Japan, to move beyond his existing program of negative interest rates and quantitative easing. Thanks to 80 trillion yen ($786 billion) a year in purchases of state debt, the BoJ owns 38 percent of Japanese government bonds—compared to the Federal Reserve's 14 percent ownership of U.S. debt—and is on track to own half by end of next year, according to Japan Macro Advisors. All that spending is getting a diminished return, said Tom Murphy, managing partner of Family Office Research and Management in Sydney. Kuroda's quantitative easing “is losing its firepower,” he said.

Let's cut to the chase.  Japanese manufacturing is international, is trade  at its most ferocious, excepting maybe South Korea.  What is the unit of account for these corporations?  The currency insurance coin.   Japanese corporation form a major component of the currency insurance market, and it is huge.  What the corporations lose on low yen rates they make up in currency hedges.  So they skip the loop, they work directly off of neutral export/import 'coins', or a pile of liquid assets bought from the currency hedger.  Their profit and loss determined by the cost of yen volatility, which they implicitly work to suppress.