Sadao Araki
Umezu was promoted to lieutenant colonel on February 8, 1922, and to colonel on December 15, 1925. During the 1920s, he was a member of the "Tōseiha", led by General Kazushige Ugaki along with Gen Sugiyama, Koiso Kuniaki, Tetsuzan Nagata and Hideki Tōjō. They represented a politically moderate line within the armed forces, in opposition to the radical "Kōdōha" movement, guided by Sadao Araki. Umezu served as an instructor at the Army Staff College from 1923–1924, and was commander of the IJA 3rd Infantry Regiment from 1924–1926.