He commanded the First Imperial Guards Division at the very end of World War II, and was killed by Major Kenji Hatanaka during the Kyūjō Incident.

A native of Kōchi Prefecture, Mori graduated from the 28th class of the Imperial Japanese Army Academy in 1916, specializing in cavalry.

He subsequently served as commander of the 13th Cavalry Regiment before returning to desk duty within the General Staff.

With the start of the Second Sino-Japanese War in July 1937, Mori was assigned as a staff officer to the Japanese First Army in China from 1937 to 1938.

[2] After Japan's decision to surrender, during a meeting with his brother-in-law, Lieutenant Colonel Michinori Shiraishi, Mori received a visit just after midnight on 15 August 1945 from Major Kenji Hatanaka, Lieutenant Colonels Masataka Ida and Jiro Shiizaki, and Captain Shigetaro Uehara, who attempted to secure his aid in their plot to isolate the Imperial Palace and to prevent the announcement of Japan's surrender.