 He served as a lieutenant in the Russo-Japanese War, where in January 1905, by direct order of Field Marshal Oyama Iwao, he led a five-man cavalry squadron on a 23-day, 1200 kilometer reconnaissance mission far behind enemy lines in Manchuria.The intelligence gathered was mentioned in dispatches by General Oku Yasukata with proving invaluable intelligence leading to the Japanese victory at the Battle of Mukden.His exploits were later publicized in a number of novels and in a serialized story for the "Shōnen Club" youth magazine, and a fictionalized version became a movie..

After the war, he graduated from the 21st class of the Army Staff College in 1909, and worked at various administrative posts within the Imperial Japanese Army General Staff.