It would probably have to be an incident where Japan provokes China near the Senkaku islands, as both these countries have strong honor codes.
The Chinese bullying works only against smaller nations, such as India, Philippines and Vietnam. When the Chinese attempt it against the powerful nations such as Russia and Japan, they get their asses kicked (remember the Sino-Soviet border conflict of 1969). And right now, the Japanese Armed Forces are much more powerful and capable, when compared to that of China. So China will wait for a few more decades, to invade the Senkaku.