In January 1943, the IJA 80th Infantry was sent to New Guinea and participated in the Battle of Lae-Salamaua and other battles. Miyake was promoted to major general in March 1944. He returned to Japan as Commanding Officer of Okayama Regimental District in April: however, in May he was ordered back to New Guinea as command of the Infantry Group of the IJA 20th Division. Miyake was at the Battle of Finschhafen against the Australian Army between September and October 1943 during the Huon Peninsula campaign, but was forced to retreat after being defeated during the Battle of Sattelberg on 25 October 1943.