>>2109347>JapsUp until the Tokugawa Shogunate (starting in 1603) the Japanese were too busy with internal disputes to make any concentrated effort at overseas imperialism. For instance, Japanese attempts at conquering Korea failed repeatedly up until the Battle of Noryang only 5 years before the rise of the Tokugawa dynasty. So realistically, there was only about a hundred and fifty years between when Japan finally got their shit together enough to organize a colony in a remote part of Asia (which, I mean, why would they?) and when the Russians reached the Pacific with their first round of colonists.
>ChineseChina as we know it today didn't really exist until the Kuomintang came into power. Prior to that, it was dynastic traditions, which were a far cry away from colonial powers. If we go back to the Yuan dynasty, then that region was just a rural backdrop to their heartlands in Mongolia, and not nearly as valuable as the developed regions that the Han Chinese had built. During the following Ming Dynasty, it was basically a frontier backwater which was only good for distracting Manchu and Mongol raiders from other, more valuable targets further south. If we follow it into the Manchu-led Qing dynasty, they were too busy trying to keep European traders, Korean and Indochinese vassals, and Japanese rivals in line to push for any serious colonization efforts.
>tl;drNobody gave a fuck about that region, and even though it changed hands a couple times throughout history, it wasn't until the Russians came that anyone bothered to live there.