I am booked on JAL flight 1 SFO-HND; coach tickets using AA award miles. There were no business class tickets available. I am wondering if the JAL counter at the airport might be willing to upgrade me by paying for it. In the past, I have upgraded from economy to premium economy on JAL by paying $300 at the airport, which was well worth it. Would they let me do the same (or upgrade to business) if I am willing to pay for it at the airport, or will the fact that this is an award ticket thru a partner airline make that impossible?

Thanks,
Reza