Are you sure?
Italy and Germany managed to effectively split Europe between them... I don't see why China and Japan wouldn't be able to split Asia between them.
One possibility:
Japan gets Korea, Taiwan, eastern Siberia, the Philippines, Indonesia, Australia, and Polynesia.
China gets Manchuria, Indochina, India, Central Asia, and western Siberia.
yes, China and Japan would hold a grudge against each other, but I think they might ally with each other against a common enemy?
Well, first of all, Italy was a lot weaker than Germany, and war between the two would have been monumentally one-sided. Japan and China are much more evenly matched.
Japan and China are also historic enemies, whereas Italy and Germany never directly fought. Germany and Italy could also initially indulge mutual expansionism (into Austria, Czechoslovakia, Ethiopia, etc.) without starting a world war. In your scenario, any Chinese expansion would require war against the European Empires, and any further Japanese expansion as well.
Italy and Germany also didn't really have any overlapping revanchist claims, other than a few mountainous parts of Austria I suppose, whereas Taiwan, which Japan stole from China in a war, is going to be a major sticking point (I'm assuming in your scenario the POD is before the annexation of Manchuria, because at that point there's no going back)
Finally, the USSR isn't really going to drive the two together; Japan and the USSR didn't go to war in OTL until literally atomic bombs were being dropped. Plus, are either of them really going to want to carve up Siberia? And is annexation of Australia really a realistic goal?
I mean, I suppose you could contrive some scenario, but realistically, two roughly matched, revanchist, militarist powers next to each other is the prime recipe for a war.