You definitely can. I have seen many times itineraries offered involving CA, OZ, and BR to/from TYO & North America.


For the OP, I don't think I'd book the BR as is if your goal is to get to Japan. If you hold out, there is a very high likelihood of OZ opening up seats on JFK-ICN and Seoul to Tokyo is pretty easy to grab on OZ or NH (note all of NH's flights are from GMP to HND, they don't do ICN anymore.) BR though unfortunately doesn't offer a lot of availability Taipei to Tokyo, so that would likely be out of pocket if you decide on the JFK-TPE ticket now. Also UA's EWR-NRT flight is one of the easier at the moment to find R space on, so also quite likely that will be available as an award closer in.

Usually I'd agree, book what's there now and change later, but the change fees for you aren't exactly cheap and knowing the route, it's not usually very difficult to get multiple C seats on as long as you stay vigilant and check frequently.