It's been a roller-coaster ride for yen pairs following the BOJ 29 July
A decent rally in USDJPY to post 103.95 has been met by month-end USD sales and that's seen the pair all the way back down to 103.25.
I had highlighted decent offers/res between 103.85-104.00 earlier in the order board and comments section and that level should still cap further rallies with stronger sell interest behind that building into 104.50.
Support/demand between 103.00-20 provides the base for the moment.
Keep an eye on the 15.00 GMT fix too where a lot of month-end business is executed to give relative transparency to corporate transactions.