The USD/JPY needs to break above the resistance trend line (red) to confirm the end of the wave 2 (purple). A push above the resistance trend line could also confirm the start of a potential wave 3 (purple) pattern towards the Fibonacci targets of wave C vs A. A break below the 100% Fibonacci level of wave 2 vs 1 invalidates (red x) the current wave 1-2 pattern.
The USD/JPY bear flag indeed turned out to be wave 4 (green) pattern. The bounce at the resistance (red) and break below support (dotted blue) confirmed the expected wave 4-5 (green) pattern. The bullish bounce now suggests a potential wave 1-2 (blue) reversal pattern as long as price action stays above the bottom of wave 1 (blue) otherwise it would become invalidated (red x).
