 He was on the staff of the Hiroshima Port Fortress, the Hōyo Strait Fortress, and commanded the Guards Field Artillery Battalion, ricing to the position of Chief of Staff of the IJA 14th Division in 1933, overseeing its withdrawal from Manchukuo back to Japan.Watanabe was promoted to major general in 1937 and was made Chief of Staff of the Central District Army in Japan.From 1938 to 1940 he head of the Army Armaments Factory.