Ships
- IJN Shiranui Captain from 10 September 1942
- IJN Arashi Captain from 15 November 1942 · In command when she was lost, 7 August 1943
Koshichi Sugioka was a commander in the Imperial Japanese Navy. Early in the Pacific War he commanded the Fubuki-class destroyer Sagiri. In December 1941 a Dutch submarine torpedoed her off Borneo and she sank. Sugioka survived. In 1942 he was again given a destroyer command.
On 10 September 1942 he became captain of Shiranui, a Kagerō-class destroyer lying in the Maizuru Naval Arsenal. In July an American submarine, Growler, had blown off her bow off the Aleutians, and the repair was expected to take many months. While he held Shiranui he also had charge of the damaged destroyers Oshio and Kasumi in the same yard. He followed Shizuo Akazawa in the ship. The appointment ended on 15 November 1942, when Hiroo Yamana took over Shiranui, still under repair.
On that same day Sugioka became captain of Arashi, a later destroyer of the Kagerō class. He relieved Yasumasa Watanabe, who had commanded her since November 1940. Sugioka joined the ship at Yokosuka, where she was finishing a short docking after escorting warships damaged in the October carrier battles back from the Solomons.
Arashi returned to the South Pacific under his command. On 22 July 1943 she sailed with the destroyers Hagikaze and Isokaze as screen for the seaplane carrier Nisshin, which was carrying tanks and other military stores to Buin. American aircraft caught the formation about twenty miles north of Shortland, short of the anchorage, and sank Nisshin. Arashi came through the attack and remained with the destroyer force.
On the night of 6 August 1943 Arashi was at sea with Hagikaze, Kawakaze, and Shigure to land soldiers on Kolombangara. Visibility was very poor. In the early hours of 7 August, in the Battle of Vella Gulf, United States destroyers found the column by radar and fired torpedoes at close range. Dunlap, Craven, and Maury were among the attackers. Arashi was hit, caught fire, and sank, with Hagikaze and Kawakaze lost as well. Shigure got away. Sugioka was killed with Arashi. About 178 of her officers and men died. On the day of the loss the navy promoted him from commander to captain.