I agree that we will not go to war with China, but Japan might.
Might means yes or no. If Japan were to respond to hostilities by China, then they would have to go all in. Otherwise, China would retaliate with commercial attacks on Japan. As in riots against Japanese goods, stores and people in China. We've seen a little of that when Japan bought the Senkaku islands from a private owner recently. It would be in Japan's best interests to counter-attack with all their might, and try to get western allies to back her.
If Japan would not counter-attack due to hostilities by China, then they might lose their only hope of resisting China as China gets stronger militarily in the near future. I can see a strong China in perhaps 15 to 20 years, that would try to subjugate Japan and Japan would be powerless. So I believe Japan should counter-attack if China initiated hostilities to Japanese aircraft.
I personally believe that Japan would retaliate. Whether the U.S.A. would back them as allies is questionable under Obama.