The Manchurian Incident broke out on September 18, 1931, and the Kwantung Army launched a surprise attack on the Chinese Nationalist Army barracks at Kanchengzi and Nanling in Changchun in response to the Liujo Lake Incident outside Mukden. The Kwantung Army occupied the area after a fierce battle and treated the casualties of the war.

　The Manchurian Incident broke out on September 18, 1931, and soldiers of the 4th Regiment, 3rd Brigade of the Kwantung Army made a surprise attack on the Chinese Nationalist Army barracks at Kanchengzi and Nanling in Changchun in response to the Liujiaohu Incident outside of Mukden. The Kwantung Army occupied the area from the Chinese Nationalist Army. After stubborn resistance by the Chinese Nationalist Army, the Kwantung Army occupied the area after a fierce battle and treated the casualties of the war.

　On the night of September 18, 1931, the Kwantung Army, a small Japanese army corps stationed in northeastern China, first took advantage of the darkness of night to secretly blow up the tracks of the South Manchurian Railway, which it had built by itself near Rattan Lake in Shenyang City. They then blamed this crime on the Chinese troops stationed there at the time. Using this as a pretext, they bombarded the northern camp of the Northeast Army of China, causing the 9.18 Incident (Manchurian Incident) that shocked both inside and outside China.

  The next day, September 19, the Japanese invaded Shenyang and began to invade the three northeastern provinces one after another. From then on, the Kwantung Army attempted to invade China completely. The Kwantung Army and the Chinese Kuomintang erupted into a long and arduous Sino-Japanese war that lasted nearly 14 years, from the September 18, 1931, incident to the Japanese surrender on August 15, 1945, in which countless Chinese and Japanese citizens fought through blood and tears, fire and water, and countless Chinese kidneys and Japanese sons and daughters, sacrificed their lives in what was considered heroic.

　On September 19, 1931, the day after the Manchurian Incident, Lieutenant General Honjo, Commander of the Kwantung Army, issued a proclamation, the contents of which were that some units of the Northeastern Frontier Defense Army of the Republic of China had fearlessly blown up the Manchurian Railway Line and taken hostile action against Japan, and that our army was compelled to take countermeasures.

　The Army Central Headquarters communicated that "the Cabinet had decided not to go beyond the necessary level in dealing with the Manchurian Incident. The Korean Command also suggested that the expansion of the war situation should be controlled as much as possible. The Army Central Command issued a directive in Telegram No. 15 at around 6:00 p.m. on September 19. The Kwantung Army Headquarters ordered the main forces of the 2nd Division to assemble in Changchun in preparation for the next operation.

　In the early morning of September 20, the 2nd Independent Defending Battalion of the Kwantung Army attacked Zhang Xue Liang's forces near Siping Street and Changzu on orders from the Kwantung Army Headquarters. It encountered fierce resistance from Zhang Xue-liang's 20th Brigade at Hongdingshan in Changzu, but was able to crush Zhang Xue-liang's army to the southwest. He then returned to Changchun and thereafter was in charge of the Changchun-Jilin railroad and Changchun security.