Thank you, everyone. Sorry about the missing information.
- American Airlines
- PIT-DFW-NRT
- U.S. citizenship, no visa (tourism < 90 days)
- I guess my plan is to sit tight for now
- I can't find what gave me the impression that layovers were not permitted. I did some more research before posting right now and I think you're correct that non-overnight layovers are permitted.
- It seems like if I want to salvage the trip with a new destination, I should try booking American Airlines so there won't be any issues departing the U.S.