Surviving the loss of his carrier at Midway, Shimakawa was reassigned to the 204th Air Group with which he was assigned to the Solomon Islands campaign in August 1942. Based on Bougainville, Shimakawa and his comrades frequently tangled with the Cactus Air Force over Guadalcanal during the battle for that island. Stricken with malaria, Shimakawa was evacuated to Japan in March 1943.