From 1939-1940, Ayabe was commander of the 25th Cavalry Regiment, based in China, and was subsequently promoted to the position of Deputy Chief of Staff of the IJA 3rd Army (Manchuria) in 1940.

From 1940-1941, he was sent on a military liaison mission to Berlin and Rome to coordinate efforts between Japan and the other Axis members of the Tripartite Alliance.

After his promotion to lieutenant general in October 1943, Ayabe was reassigned to the Southern Expeditionary Army Group as Deputy Chief of Staff and was based in Singapore.

However, he was badly injured in an airplane crash in February 1944, and was assigned to staff duty in Tokyo through the remainder of the war.

[2] Ayabe retired from active military service with the dissolution of the Imperial Japanese Army at the end of World War II.