JPMorgan is trying to compare this to Dec 2009, which I have circled in the chart:
"There have only been two instances since the Fed started its zero interest rate policy, when the USD was strong at the cost of the JPY – February 2009 and December 2009. Particularly, the latter month saw a risk rally, which is a better resemblance of the current situation. USD/JPY rallied about 10.5% in December 2009. If we see a rally of the same magnitude this time around, the pair could reach 84. That being said, we still believe USD (and hence USD/JPY) upside is limited unless we see a sharp rise in UST yields".