The selling above 91.25 this morning in the USD/JPY is being attributed largely to profit-taking by funds.
There is Japanese exporter sell interest higher too (to an extent, there is always Japanese exporter sell interest in USD/JPY, so this isn’t particularly insightful).
The 90.95/91.00 I spoke of as initial support earlier on has held up well so far; there is more buying done around 90.85/90.