The Second General Army was established on April 8, 1945 with the dissolution of the
General Defense Command into the
First and Second General Army. It was essentially a
home guard and
garrison, responsible for
civil defense,
anti-aircraft defenses, and for organizing guerrilla warfare cells in anticipation of the projected
Allied invasion of the
Japanese home islands in
Operation Downfall (or in Japanese terminology). Although its territory encompassed all of western Japan, its primary mission was to ensure the security of southern Kyūshū, which was regarded as the most probable target for invasion. Its forces consisted mostly of poorly trained
reservists,
conscripted students and
home guard militia. After the
fall of Okinawa, the command of the Second General Army was relocated to
Hiroshima. When the
atomic bomb was dropped on Hiroshima, most of the military units, logistical arms, and command staff of the Second General Army were killed, although Hata himself was slightly wounded. Together with the
Fifth Division,
Fifty-Ninth Army, and other combat divisions in the city who were also hit, an estimated 20,000 Japanese combatants were killed. Survivors regrouped at Ujina Air Base at the outskirts of Hiroshima, where they organized relief efforts and maintained public order in Hiroshima once
martial law was proclaimed. However, the atomic bombing ended the Second General Army as an effective military organization for Imperial Japanese Army units in western Japan. Elements remained in place under the
American occupation authorities until November 1945 to assist with the demobilization of Japanese troops. ==Commanders==