Originally Posted by
RetiredATLATC
Ive thought about that and have also spoken to a few "digital nomad" friends who say when they run into these sort of problems they use a company called onewayfly that'll "book" them a ticket to be able to show the return/exit. I'd never heard of them before.
That company just sounds like a TA that creates a PNR for you without ticketing. The PNR/reservation is then what you'd use to show a return/onward flight.
But to answer your original question, I've been asked ~50% by both JAL and ANA for onward flights when I've only booked a one-way with them.