Either the Japanese have got to learn how to live with their conquests, or they kill them all and make those conquests meaningless. What would it mean for the Japanese if they killed all the inhabitants of Korea and move in Japanese citizens to replace them, would it be much of a conquest? What if they killed all the Chinese in the Chinese provinces they controlled at great cost in Japanese soldiers lives only in the end to conquer an land mass with a lot of skulls and corpses plowed into the dirt, would this sort of "victory" enhance the Japanese Empire in anyway other than giving it more land to occupy? More coal to mine perhaps? I think the majority of the value of the conquests would be in the people they conquer, natural resources are meaningless without people to mine them, and in order to use the people they conquer, they have to make use of their talents, and some of those talents would naturally fall into the territory of administering their Empire, and in order to do that a sort of "working relationship" would have to be established so they are not constantly putting down rebellions all the time and costing Japanese soldiers their lives in putting down the insurrections. I think Chinese peasants work more efficiently if they are allowed to do so for their own sakes and economic benefit rather than requiring Japanese soldiers to point guns to their heads all the time. The Japanese soldier for his part would like to go home to his family once the war is over, and for that to happen the war and the constant fighting has to end or at least peter down to a more tolerable level. The majority of the Chinese will have to accept that they've been beaten and come to some sort of accomodation with their new rulers, and some of those Chinese will rise up within that system - without that happening the Japanese Empire will eventually fall apart. There is an inherent contradiction between conquering one's neighbors and retaining one's original character. If Japan's was to be a lasting Empire it would have to eventually absorb the cultural influences of those they have conquered, so the Japanese of the Japanese Empire won't be quite so "Japanese" as in OTL.