Ships
- IJN Hosho Captain from 1 August 1942 · Relieved on 15 November 1942
Bunjiro Yamaguchi was an officer of the Imperial Japanese Navy who commanded the aircraft carrier Hosho in the late summer and autumn of 1942 and ended the war as a rear admiral. He was born on 5 February 1896. He graduated sixth in the 45th class of the naval academy, a class of eighty-nine, and afterward attended the torpedo school, the gunnery school, and the 27th class of the Naval Staff College.
From 1 December 1930 he served on the Naval General Staff, in the first section of the first bureau. In February 1932 he was briefly attached to the staffs of the 2nd Fleet and the 3rd Fleet, and on 15 November 1932 he became a staff officer of the 2nd Fleet. At an earlier point in his career he had been executive officer of the battleship Yamashiro. He returned to the Naval General Staff in November 1934. The next month he was sent to reside in the United States, and on 31 October 1935 he was appointed assistant naval attaché at the Japanese embassy there. He was ordered home on 20 October 1936.
Staff duty occupied him through 1937. On 26 March 1938 he became an instructor at the Naval Staff College, and from 15 July that year he also taught military science at the Army War College. On 6 May 1940 he was made chief of the fifth section of the third bureau of the Naval General Staff. From 1 April to 30 May 1941 he was away on duty in the United States and Mexico, then resumed the same section. In January 1942 he was again assigned as an instructor at the Army War College while keeping the staff post. On 15 May 1942 he added the job of chief of the second section of the Navy information department at Imperial Headquarters. On 10 July 1942 he was attached to the Yokosuka Naval District.
Hosho was already twenty years old. Built at Tsurumi and completed in December 1922, she was the first aircraft carrier designed as such to enter the Japanese navy. Jiro Toshima saw her through fitting out and took command as she joined the fleet. Heizaburo Fukuyo relieved him on 1 April 1923, and Ryutaro Kaizu followed on 1 December 1923. Seizaburo Kobayashi commanded her from 15 April 1925, Giichiro Kawamura from 1 November 1926, Kiyoshi Kitagawa from 1 December 1927, and Goro Hara from 10 December 1928. Hideho Wada took command on 30 November 1929, Eijiro Kondo on 1 December 1930, Rokuro Horie on 14 November 1931, Teizo Mitsunami on 1 December 1932, and Rokukichi Takeda on 20 October 1933. Larger carriers had taken over the striking work, and Hosho spent much of her later life training aviators in home waters, though she could still keep the sea with the battle line.
In December 1941 she sailed with the Main Body, giving distant cover while the carriers struck Pearl Harbor, and she was back at Kure within a few days. On 29 May 1942 she left again with that body for the Midway operation, carrying eight obsolete biplane torpedo bombers and staying well behind the carrier striking force. On the morning of 5 June one of her aircraft photographed the burning carrier Hiryu. Hosho returned to Hashirajima on 14 June. Her planes were then put ashore. On 14 July she moved from the 1st Fleet to the 3rd Fleet and began landing exercises, with the destroyer Yukaze as her guard ship.
Yamaguchi became captain of Hosho on 1 August 1942. On 14 August she was assigned to the standby force of the Mobile Force, still in the Inland Sea, and she arrived at Hashirajima on 17 August. A plan to send her on an aircraft-ferry run to the Marshall Islands was dropped, and she was ordered to Kure. On 15 September she entered drydock to be fitted for training new aircrews in carrier landings. She left the dock on 23 September. On 20 October she reached Kitsuki on Kyushu and joined the Mobile Force Training Force, remaining under the 3rd Fleet for administration. For the rest of his time in command her deck was a school for pilots. He was relieved on 15 November 1942, and Katsuji Hattori succeeded him.
On 25 November 1942 Yamaguchi was attached to the 3rd Fleet. On 5 December he became captain of the light carrier Zuiho, and that command ended on 5 July 1943, when he was again attached to the Yokosuka Naval District. On 13 August 1943 he was appointed chief of staff of the Osaka Guard District. He was promoted to rear admiral on 1 November 1943. From 20 May 1944 he also headed the district's supply department. On 26 February 1945 he returned to an attachment at the Naval General Staff. Yamaguchi died on 3 January 1948.