Welcome to FT!

It may be easier to break your cities up. I just looked at the trans-pac flights.

I found (using the ANA Star Alliance tool):

Asiana has Biz seats Seoul-SFO-Seoul on your departure and return

ANA has Biz SFO-NRT for the return.

Asiana has Biz outbound and First and Biz return ICN-LAX-ICN on your dates.

AC has Biz HKG-YVR on your outbound.

Thai has BKK-LAX in Biz on the 14th.

SQ has a seat LAX-NRT in Biz on Dec 28

UA has SEA-NRT in First on Dec 28.

Now, the fact that the ANA site shows these does not always mean that UA has them. But I have found it to be a good indication.