I think that the Yen will have a bit of strengthening before it will weaken again.
Yesterday I have done a technical analysis on the long-term view of USDJPY. Now, I understand that it's not the same as NZDJPY, but looking at the chart right now, I believe that there is still some potential to the upside. It seems that it is forming a typical textbook Elliott Wave scenario, where it completed wave 3 (2nd impulse wave). I think a small retracement to around 81.400 would be quite healthy for this pair, before shooting off to test the 2017 July high.
Of course, this is just an idea. But the way everything is forming right now, I think it could be the case.