I'm pretty sure it's just 24 hours, EDIT - Well strike that, it's 72 hours... but having said that if on separate tickets then no one would be the wiser once Japan is open for entry, just don't attempt to check luggage through, they'd have to go pick it up from baggage claim and go check in again as if a local passenger. (tear off your old baggage tags before getting to the JL counter, that would be a dead giveaway)

I found this, which could be useful, basically buy it on separate tickets, and keep your mouth shut about what you're doing to everyone.
Philippine Airlines instructions to agents on US Cabotage

AA doesn't fly Japan to Hawaii (which is where it sounds like the OP is trying to go), that's just UA and HA these days for US carriers, plus NH and JL. Scoot used to from KIX, not sure if that resumed or not.