Barracks of the former Fifth Cavalry Regiment.
Source: Hiroshima History New Edition, Vol. 2
Second General Army Headquarters
In early 1945, with Japan's war situation worsening, the Imperial Headquarters decided to prepare for a “decisive battle for the mainland” and began calling loudly for "100 million deaths with honor." On April 7, 1945, a new Army Air Force Headquarters was established along with First and Second General Army Headquarters that divided Japan's mainland into eastern and western territories along the Suzuka Mountain Range.
This move was preparation for the possibility that the mainland would be split by advancing American troops, and the Second General Army Headquarters was located in Hiroshima in the barracks of the former Fifth Cavalry Regiment at Futabanosato. This headquarters further strengthened Hiroshima's role as a military city.