Government and BOJ intervened on April 30, buying yen and selling dollars, pulling USD/JPY down 2.3% to 156.57, its highest since July 2024.
The U.S. dollar index fell 0.9% to 98.06 as the Fed kept rates unchanged and signaled uncertainty amid Middle East conflict.
ECB and BoE also held rates steady, with the euro up 0.4% to $1.1732 and sterling rising 1% to $1.3607.
Oil prices remained on track for April gains despite earlier spikes, while U.S. President Trump prepared for possible Iran strike briefing.