I really doubt the ECB bought much EUR/JPY today. Why? Look at yields on the short-end of the yield curve.
Central banks like to keep their intervention proceeds pretty liquid, so you go to the short-end of the curve.
US two year note yields are essentially unchanged on the day while in Germany they are up 10 bp on the day.
The EUro is getting a boost from the widening interest rate differential, once again.