关东军
In August 1945, the Kwantung Army was engaged by Soviet troops during the Manchurian Strategic Offensive Operation. The Kwantung Army surrendered to the Soviets the day after the Surrender of Japan and was subsequently dissolved. The Kwantung Army was responsible for many of the worst Japanese war crimes during World War II, including the sponsorship of Unit 731 which performed biological warfare and human experimentation on civilians and prisoners of war.