If you can get yourself to Seoul, and your company will pay for a ticket from there, AA has one-way fares from ICN-DFW for US$1358 in August, as opposed to US$3300 from NRT!
And yes, you fly from ICN-NRT on JL and get on the exact same flight from NRT that would have cost US$3300
Don't ask why; it's one of the many quirks of airline pricing systems.

Happy Travels.