Originally Posted by VegasGambler

It's all but certain that JL will open SFO-TYO J (and most likely F) space a could of weeks before departure. They generally open up almost all their available inventory to awards a couple of weeks out.

Eg, search for SFO-TYO for the next week or two. It's wide open (same with other west coast gateways)

I would feel very comfortable booking Y (or mixed cabin) with the expectation that I would be able to change the TPAC to J or F two weeks out. You may even be able to get all 3 on the same flight (but the nice thing about leaving from SFO is that there are multiple flights/day, so if you are on being on different planes you have much better chances of finding the space you want, assuming you are ok with either HND or NRT. But, looking at availability in the next few weeks I see many flights with 3+ award seats in J and/or F so there's a decent chance that that won't be necessary.