Thanks everyone for help. I finally manage to book 2 xTYO for DONE4 for $6,000 USD through AA. Base fare $5,300. Tax + Other charges 700. I did not try to optimize surcharges, perhaps it can be even cheaper than that.

Here are my itineraries

TYO -> xDFW -> BUR (JL)(Even though EF shows 9 D fare from TYO -> LAX, but AA is not able to book it) BUR works well for me because it has direct flight from DFW where I can catch long haul flights. Also online tool does allow me to select LAX twice unless visiting another north America city, so during planning I just use Burbank. Burbank can trick online tool.
BUR -> xDFW -> SCL (AA)
SCL -> xDFW -> LAX (AA)
LAX -> ANC (AS)
ANC -> LAX (AS)
LAX -> xDOH -> CAI (QR)
IST -> xDOH -> MLE (QR)
MLE -> CMB -> PEK (UL) may switch to QR later
PEK -> TYO (JL)

All flights beside the first flight are placeholders. I will need to call AA multiple time to change everything. If anything I need to watch out please let me know. So far it does not seem like I can select seats from QR by using record locator (same locator for all airlines) from AA. I can see all my flights through QR, but when I attempt to select seats, it also show something went wrong, please contact us.