If a real Yen recovery is desired, there would have to be a real change of direction in monetary policy. And I don't mean a symbolic end to the symbolic negative-rate policy! But why should that happen as long as the BoJ is firmly convinced that inflation will fall back below the 2% target?

If the FX market really falls for a symbolic rate hike and interprets it as JPY positive or the start of a rate cycle, then that would be a better tool for strengthening the JPY than intervention. In short, it is the Bank of Japan, not the MOF, that holds the key to sustainable JPY stabilization.