I summarised the Bank of Japan September meeting minutes here:
In (very) brief, the minutes reinforced the Bank's cautious stance on policy normalisation. Members agreed real rates remain very low and that gradual hikes may continue if inflation holds, but trade risks and uncertainty over U.S. tariffs warrant patience. Views diverged on timing, with some citing rising underlying inflation and broadening price pressures, while others warned expectations remain fragile. The minutes showed officials still wary of Japan’s deflationary past, but encouraged by signs that the impact of U.S. tariffs and food costs is smaller than feared.
There really wasn't a smoking gun to explain this yen strength.
Safe haven flows with equities weak accounting for the yen bid.