Despite the expensive reconstructions , both vessels were considered obsolete by the eve of the Pacific War , and neither saw significant action in the early years of the war . Following the loss of most of the IJN 's large aircraft carriers during the Battle of Midway in mid @-@ 1942 , they were rebuilt with a flight deck replacing the rear pair of gun turrets to give them the ability to operate an air group of floatplanes . A lack of aircraft and qualified pilots , however , meant that they never actually operated their aircraft in combat . While awaiting their air group the sister ships were sometimes used to ferry troops and material to Japanese bases . They participated in the Battle of Cape Engaño in late 1944 , where they decoyed the American carrier fleet supporting the invasion of Leyte away from the landing beaches . Afterwards both ships were transferred to Southeast Asia ; in early 1945 they participated in Operation Kita , where they transported petrol and other strategic materials to Japan . The sisters were then reduced to reserve until they were sunk during American airstrikes in July . After the war they were scrapped in 1946 – 47 .