“Tokyo’s ability to determine Japan’s destiny evaporated in 1931 when junior officers in Japan’s Kwangtung Army Headquarters in Manchuria decided, on their own initiative, to expel Chinese forces from the province and create an independent Manchurian state under Japan’s control. The Kwangtung officers began planning the complex operation that summer, and they coordinated their scheme with the Sakurakai (Cherry Blossom Society), a secret clique of young, ultranationalist officers of the Army’s General Staff Headquarters in Tokyo.”
– Compellence and the Strategic Culture of Imperial Japan: Implications for Coercive Diplomacy in the Twenty-First Century, Forrest E. Morgan, 2003
From the wiki: “The Imperial General Staff Headquarters was established in 1893 [at Miyakezaka, across from the Imperial Palace] to coordinate efforts between the Imperial Japanese Army and Imperial Japanese Navy during wartime. In terms of function, it was approximately equivalent to the United States Joint Chiefs of Staff. The Emperor of Japan who was defined as both Head of State and the Generalissimo of the Imperial Japanese Armed Forces according to the Meiji Constitution of 1889 to 1945, was the head of the Imperial General Headquarters, and was assisted by staff appointed from the Imperial Japanese Army and Imperial Japanese Navy. The Staff Headquarters was completely independent of the civilian government of the Empire of Japan, including the Cabinet and even the Prime Minister of Japan.
“During the Pacific War, and after the firebombing of Tokyo, in March, 1945, the Imperial General Headquarters relocated to an underground facility at Matsushiro in the mountains outside of Nagano. With the surrender of Japan, the Supreme Commander of the Allied Powers ordered the Imperial General Headquarters abolished on 13 September 1945.”