The summary of the Bank of Japan policy statement and outlook report is here:

USD/JPY rocketed higher. There had been some market expectations of further policy change to come from the BOJ after December's widening of the 10 year JGB yield band and the subsequent further intense selling pressure on JGBs. Yen longs were one expression of this expectation.

USD/JPY has been marked instantly higher and, as I post, its holding near session highs:

usdyen 1 minute bars 18 January 2023

This is the one-minute candle chart. If you are lying in bed staring at your phone it'll give a flavour of the move.