Ships
- IJN Hosho Captain from 14 November 1931 · Relieved on 1 December 1932
Rokuro Horie was a career officer of the Imperial Japanese Navy. Born on 25 August 1886, he graduated in the 36th class of the Naval Academy, standing 58th in a class of 191, and afterward passed through the gunnery school, the torpedo school, and the 19th class of the Naval Staff College. Those courses were the ordinary path for a line officer headed toward sea command and staff duty. He rose to vice admiral and died on 14 February 1972.
On 14 November 1931 he took command of the carrier Hosho, relieving Eijiro Kondo. Hosho had entered service in 1922 as the first Japanese warship designed from the keel with a continuous flight deck, and for years she was the ship on which the navy learned how to launch and recover aircraft at sea. Horie joined her at Yokosuka while she lay in dock for engine repairs. She came out of the yard on 23 December 1931.
The Shanghai fighting pulled her south almost at once. Hosho left Yokosuka on 29 January 1932 in company with the carrier Kaga. She carried a naval landing force of 408 men, twenty of them warrant officers or above and 388 petty officers and sailors, together with weapons, ammunition, food, and clothing. Off the mouth of the Yangtze the men and their stores were transferred to destroyers, and that work ended on 1 February. From 5 February the carrier's airmen flew from a field in Shanghai. On 8 February their aircraft bombed the forts at Wusong, downriver from the city, and fighters from the group covered attack planes over the fighting. Horie remained captain of the ship through the operation. On 20 March 1932, once the emergency had passed, Hosho was placed in reserve, and he kept the command through the quieter months that followed.
He was relieved on 1 December 1932 by Teizo Mitsunami. The same day he became commander of the Tateyama Naval Air Group, so his next duty stayed with naval aviation, this time at a shore station. On 1 November 1934 he returned to sea as captain of Akagi. She was one of the fleet's large carriers, finished from a battlecruiser hull, and the air group under his hand was far bigger than anything Hosho had carried.
He left Akagi on 15 November 1935. On 1 December 1937 he took command of the Kasumigaura Naval Air Group, the large training station on the lake northeast of Tokyo where naval pilots were taught to fly. The post sat squarely on the path he had followed since Hosho, from a flight deck to the shore establishments that supplied aircraft and crews to the fleet.
On 15 November 1940 Horie was promoted to vice admiral and attached to the Naval General Staff. On 15 March 1941 he was placed among the officers awaiting orders, and on 20 March he transferred to the reserve. The year he spent in Hosho had put him on the navy's original carrier in the winter she first sent her aircraft into combat, off Shanghai in 1932.