Will my trip qualify for the 144 hours Waiver? or do I even need a Visa since I have a US passport?

I will be arriving into CSX from HND on 12/16/24 and will be flying to NRT from CSX on 12/18/24, basically going from Japan back to Japan (staying in Changsha for only 2 days) and not continuing on to a "Third" country region.
I have a US passport; do i need a Visa? Thanks in advance!