Check this out for why now is a particularly effective time of day to intervene, at the cost of looking desperate and weak:

Still, the cheapskates at the Bank of Japan will take it!

usdyen boj intervention 02 May 2024 222

What this has done is leave a huge 'gap' from 157.50 to where we are now, give or take. Over coming days and weeks that's the target for filling in.