I want to go to China from Japan this August for a short trip. I will visit both Shanghai and Beijing, but the order in which I visit them won't matter at all. The ticket would just need to be an open jaw...

Is it easy to book a flight from Japan (preferrably HND or NRT, but I guess KIX would be okay) to China using AAdvantage miles? I don't know when exactly in August I want to go, and I planned on getting this together around March. Should I try to do it as early as possible, or will waiting around then be fine? I had pretty good luck doing NRT-TPE and NRT-HKG, but that was on ANA.

Thanks!