Background to China
Puyi: Japanese figurehead of Manchukuo
With the help of the Meiji Reformation in 1868, Japan quickly modernized. As Japan preened herself in preparation for a rise in global power, they became interested in Korea. At the time, however, Korea was under the influence of Qing China. Coincidentally, Qing China was falling in power and more so if she were to be compared to Japan. The Qing had just suffered heavy losses with the Opium War and other internal troubles. In comparison, Japan was growing in prominence and power. Ultimately, China was unable to dominate their once quiet neighbor in the First Sino-Japanese War, and lost Korea.
In the 1931 Mukden Incident, China suffered another loss at the hands of the Japanese: Manchuria. The incident was planned by the Japanese Imperial Army as a reason for a Japanese invasion. After a Japanese invasion, Manchuria became Manchukuo, a Japanese puppet-state that installed Puyi as its figurehead. Incidentally, this ploy was eventually unraveled, leading Japan to leave the League of Nations. Now that Japan's hands were free, Japanese troops could stay in mainland China. And indeed Japanese troops remained in Manchuria until they were forced out by Soviet troops near the end of WWII.
In the 1931 Mukden Incident, China suffered another loss at the hands of the Japanese: Manchuria. The incident was planned by the Japanese Imperial Army as a reason for a Japanese invasion. After a Japanese invasion, Manchuria became Manchukuo, a Japanese puppet-state that installed Puyi as its figurehead. Incidentally, this ploy was eventually unraveled, leading Japan to leave the League of Nations. Now that Japan's hands were free, Japanese troops could stay in mainland China. And indeed Japanese troops remained in Manchuria until they were forced out by Soviet troops near the end of WWII.
Chinese propaganda against Japanese occupation
The growth of their neighbor greatly affected China's own domestic affairs. For one, the Chinese Civil War was put on hold because the Kuomintang and Chinese Communist Party banded into a Second United Front to fight Japanese troops. Though this United Front was quite superficial, it fostered trust between the people and the CCP. The CCP interacted with the people on a more personal level than the KMT ever dared to. The CCP employed guerrilla war tactics that would not have been possible without the help of locals. Without a doubt, support for the CCP grew substantially from this.