After the end of the war, he attended the Imperial Japanese Army Academy, and on graduation in June 1897 was assigned to the IJA 7th Infantry Regiment.

From 1921 to 1923 he was the head of the Preparatory Course at the Imperial Japanese Army Academy, followed by a time attached to the Inspectorate General of Military Training.

On the day after the Mukden Incident on 19 September, he ordered the IJA 20th Division to split its force, forming the 39th Mixed Brigade.

Acting without authorization by the Emperor or central government in Tokyo, Hayashi ordered the 39th Mixed Brigade to cross the Yalu River that same day into Manchuria.

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.

The struggle between the Tōseiha and Kōdōha factions continued below the surface of the government; and the war in North China carried on apace until February 1936.

Hayashi also happen to the president of Greater Japan Muslim League (大日本回教協会, Dai Nihon Kaikyō Kyōkai).

[3] Hayashi served as Prime Minister of Japan for a brief four-month period in 1937, where he tried to establish a cabinet that rose above the factional strife of the political parties.