The Japanese 44th Army was initially raised in July 1941 as the Kwangtung Defense Army (関東防衛軍, Kanto boei gun), an auxiliary force of the Kwantung Army based in the Manchukuo capital of Xinjing for public security and training.

As the war situation on the Pacific front grew increasingly desperate for Japan, the Imperial Japanese Army transferred more and more experienced divisions and their equipment out of Manchukuo to other fronts.

By early 1945, the vaunted Kwantung Army was largely hollowed out, and indications of a buildup of Soviet Red Army forces on the borders on Mengjiang and Manchukuo were alarming.

It saw combat against the Soviet Army in Soviet invasion of Manchuria, with combat operations continuing into September, even after the official surrender of Japan.

It was officially disbanded at Mukden, with many of its surviving troops becoming Japanese prisoners of war in the Soviet Union.