A basic tenet of is that "history repeats itself". My hypothesis is that USDJPY moves in 2012-2016 are similar to its moves in 1995-1997. The current down move in USDJPY will end at around 107.00-30, from which it shall reverse up strongly in coming months to well above 140.00, just like it did in 1997-1998.
The low at 75.50 in 2012 was the start of the current big up trend. The high of 125.80 in 2015 was wave(3). Thereafter until now, it has been doing a wave(4) correction. In 1997, wave(4) retraced 38.2% of wave(3). I believe the current wave(4) will also bottom out near its around 107.20.
Once the wave(4) is completed, the initial reversal to start wave(5) will be powerful. The eventual peak for wave(5) could be well above 140.00 over 12-18 months.