The first headlines and BOJ analysis from the US is starting to roll out on the wires
There's no news to go with the drop in yen pairs. USDJPY has dropped below 101.00 to 100.96 and GBP & EUR yen crosses have also gone back to the lows.
We can see when the yanks started warming up in their morning because the stories from the US start hitting the news reels.
Cable and the euro are still doing nothing so this is purely a reaction from traders playing catchup.