|Born||October 2, 1891
Nagano Prefecture, Japan
|Died||24 June 1985(aged 93)|
|Allegiance||Empire of Japan|
|Service/branch||Imperial Japanese Navy|
|Years of service||1912-1947|
Cruiser Division 18
|Battles/wars||World War II
Battle of the Coral Sea
|Other work||Naval attache to Manchukuo|
As a midshipman, Marumo served on the cruisers Soya and Kashima, and as an ensign, on the battleship Mikasa. After completion of his torpedo and naval artillery training, he was assigned to the battleship Aki.
In 1917, Marumo was assigned to the 2nd Special Task Fleet under Admiral Kozo Sato, a task force of Japanese destroyers deployed to Malta in the Mediterranean as part of Japan’s assistance to the Allied war effort under the Anglo-Japanese Alliance. After his return to Japan in 1918, he was promoted to lieutenant and assigned to the cruiser Tone. In 1921, he became chief gunnery officer on the destroyer Okikaze, and later that year was made executive officer on destroyer Tachikaze. He subsequently served as chief gunnery officer on the cruiser Nisshin and battleships Ise and Hyūga. After his promotion to lieutenant commander in 1924, he was assigned to the cruiser Yakumo, battleship Yamashiro and destroyer Kako. In 1929, he made commander, and joined the Imperial Japanese Navy General Staff in a number of shore assignments. He served as a military attaché to the United States and Europe from December 1933-July 1934.
In December 1937, Marumo was given his first (and only) command: the heavy cruiser Ashigara. From 1938-1939, he was assigned to the Kure Naval District. Marumo was promoted to rear admiral in November 1939.
From December 1942, Marumo was assigned as naval attaché to the Empire of Manchukuo, where he spent most of the remainder of the war. He was promoted to vice admiral in November 1943. Repatriated to Japan in July 1947, Marumo in retirement until his death in 1985.
- Morison, Samuel Eliot (2001) . Coral Sea, Midway and Submarine Actions, May 1942-August 1942, vol. 4 of History of United States Naval Operations in World War II. Champaign, Illinois, USA: University of Illinois Press. ISBN 0-252-06995-1.
- Nishida, Hiroshi. "Imperial Japanese Navy".
- United States Strategic Bombing Survey (Pacific) - Naval Analysis Division (1946). "Chapter 4: The Battle of the Coral Sea". The Campaigns of the Pacific War. United States Government Printing Office.
- Nishida, Imperial Japanese Navy.
- Morison. Coral Sea, Midway and Submarine Actions, May 1942-August 1942