was an Imperial Japanese Army commander of the Chosen Army of Japan in Korea during the Mukden Incident and the invasion of Manchuria, and a Japanese politician and the 33rd Prime Minister of Japan from February 2 1937 to June 4 1937.
In 1930, Lieutenant-General Senjūrō Hayashi, was made Commander in Chief of the Chosen Army, in Korea. On the day after the Mukden Incident on September 19th, he ordered the IJA 20th Division to split its force, forming the 39th Mixed Brigade. The Japanese cabinet, however, disagreed with the army, suspecting that the Mukden Incident was a conspiracy by Japanese army officers. Without authorization by the Emperor, Hayashi ordered the 39th Mixed Brigade to depart that same day for Manchuria. The cabinet finally conceded the point to the military and the movement of the 39th Mixed Brigade from Korea was authorized on September 22nd.
Following his command in Korea, Hayashi was made Inspector-General of Military Training and a member of the Supreme War Council from 1932 to 1934. From 1934 to 1935 Hayashi was Army Minister, and from 1935 to 1936 again member of the Supreme War Council.
Hayashi was a supporter of Sadao Araki, along with Shigeru Honjo who was commander of the Kwantung Army. The Toseiha faction within the Imperial Japanese Army scored a victory in January 1934 when General Araki was forced to step down, after the excesses of the Kwantung Army, and his replacement was one of their own, General Hayashi. The struggle between the Toseiha and Kodaha factions continued below the surface of the government; and the war in North China carried on apace until February 1936.
Hayashi also promoted Fumimaro Konoye's doctrines, as a "right-winger" amongst the militarists, who approved of the "fiction" of democracy, and the Emperor's role with an "adviser group", againsy "left-winger" radical militarists. The latter, led by Kingoro Hashimoto, wanted a Military Shogunate (under the patronage of Baron Hiranuma).