Ships
- IJN Hosho Captain from 5 September 1941 · Relieved on 1 August 1942
Kaoru Umetani, a captain in the Imperial Japanese Navy and a graduate of the Naval Academy’s 46th class, took command of the carrier Hosho on 5 September 1941. He came from duty as executive officer of the carrier Akagi and relieved Captain Tomozo Kikuchi. Hosho, completed in December 1922, was the first aircraft carrier the Imperial Navy finished for that role. Jiro Toshima had commanded her when she entered service, and Heizaburo Fukuyo and Ryutaro Kaizu were among the captains who followed in the 1920s. By the time Umetani arrived she was a training ship, small beside the fleet carriers then in service, and her aircraft were older Type 96 fighters and Type 96 attack planes.
The flag of Carrier Division 3 left Hosho on the day he assumed command. On 17 September she sailed from Hashirajima and reached Kure the same day. On 20 September she and the supply ship Mamiya anchored near a fitting-out pontoon beside the unfinished battleship Yamato, with the heavy cruisers Kako and Kinugasa nearby. On 28 September the division flag returned to Hosho for a single day. Her air group that autumn was eleven Type 96 carrier fighters and eight Type 96 carrier attack planes.
At the start of the Pacific War Hosho remained in Carrier Division 3 of the First Fleet with the carrier Zuiho. Their work was scouting, anti-submarine patrol, and a thin air screen for the Combined Fleet’s battleship force, which included Nagato, Mutsu, Fuso, Yamashiro, Ise, and Hyuga. The ships left the Inland Sea as the Hawaii operation went forward and passed the Bungo Strait on 8 December 1941. On the evening of 10 December an aircraft reported a United States submarine trailing the formation. Umetani launched planes even though they could not return before dark, then ordered the flight-deck lights switched on so the aircraft could land. The lighted deck drew no attack. The recovery slowed Hosho, she fell out of formation, and she rejoined the fleet on 11 December.
On the return through the Bungo Channel the destroyer Sanae attacked a reported submarine that was not there, and a rumor reached Kure that Hosho had been sunk. Admiral Isoroku Yamamoto, commander in chief of the Combined Fleet, met Umetani with a smile and teased him about his brief turn as a destroyer-squadron commander. The carrier was undamaged.
In March 1942 Hosho left Hashirajima to search for an American force reported in home waters, then came back to the Inland Sea. On 29 May she sailed again with the Main Body for the Midway operation, in company with Yamamoto’s flagship, the battleship Yamato. Her small air group flew searches in bad weather. Matome Ugaki, chief of staff of the Combined Fleet, recorded that Hosho had carried out her task with those few aircraft and that the effort deserved praise. She anchored off Iwakuni on 14 June.
After Midway the navy kept Hosho in the Inland Sea for deck-landing training and as a target ship for submarines. Umetani later compared that duty to the work of a nurse in a kindergarten. On 1 August 1942 Captain Bunjiro Yamaguchi relieved him. Umetani later rose to rear admiral.