In Chinese history, the relationship between China and Japan has always been a delicate topic. During the Tang Dynasty period, Japan regarded China as its "idol" and sent envoys from the Tang Dynasty to China to learn Chinese culture. But in modern China, Japan twice provoked war between China and Japan. Especially during the war of aggression against China in 1931, Japan caused great harm to the Chinese people.
However, with the unity of the Chinese military and civilians to resist Japan and the establishment of the World Anti-Fascist Alliance, Japan announced its surrender in 1945. The Soviet army also launched a massive attack on the Kwantung Army in the Northeast in 1945 and captured many Japanese female soldiers. However, the Soviet army's handling of Japanese prisoners still scares Japan to this day.

Around 1929, an unprecedented economic crisis broke out in the capitalist world, and this crisis also swept across Japan. Before the economic crisis , Japan's economic situation was excellent, and it seemed to have entered the ranks of the world's advanced countries.
After the economic crisis broke out, many factories in Japan closed down and the unemployment rate of workers increased. Many Japanese citizens expressed their dissatisfaction with the Japanese government. At this time, Japan's right-wing forces took the opportunity to gain support in Japan and established a fascist regime.
Japan attempted to launch a war to obtain industrial resources, revitalize the entire country's economy, and divert domestic conflicts. Therefore, Japan focused on the resource-rich Northeastern region .

Emperor Hirohito
So, in 1931, the Japanese created the "September 18th Incident". The Japanese Kwantung Army invaded and occupied the land of Northeast China.
In 1937, the all-out Anti-Japanese War began. When the all-out resistance just started, the Japanese clamored for "destroy China in three months." However, Japan underestimated China's strength, and China and Japan launched a protracted war. Not only that, the ambitious Japan also tried to harass the United States, but unexpectedly dragged itself into the quagmire of the Pacific War.

Japan is trapped in the Chinese battlefield and Pacific battlefield unable to extricate itself. The protracted war not only consumes Japan's national power, but also consumes Japan's military strength. After Japan fell into a situation of tight military resources, it had to recruit some child soldiers and female soldiers.
As Japan’s military resources continue to be depleted, Japanese Boy Scouts and female soldiers need to assume more combat responsibilities. But after the United States dropped two atomic bombs on Japan in 1945, the United States almost crushed Japan's war plan.
At the same time, the Soviet Red Army had liberated Germany. Therefore, the millions of Soviet Red Army turned their guns and began to aggressively attack Japan's "Million Kwantung Army" in the Northeast. In the face of the Soviet mechanized troops, the Kwantung Army was defeated. Many male soldiers were directly strangled by the Soviet army, while Japanese female soldiers became a tool for the Soviet army to express their sexual desires.

The Soviet Union attacked Japan's Kwantung Army, completely crushing Japan's invasion plan. The Japanese Emperor announced an unconditional surrender.
After Japan surrendered , Japan hoped that the Soviet Union could release Japanese male and female prisoners of war. However, Japan at that time had surrendered to the United States and was politically inclined to move closer to the United States. Therefore, the tough Soviet Union returned jars of ashes to Japan as a warning to Japan.
The actions of the Soviet Union still frighten Japan to this day. Perhaps this is one of the reasons why Japan is still afraid of Russia.