Ships
- IJN Natsushio Captain from 20 October 1941
Commander Sumitaka Nagai of the Imperial Japanese Navy became captain of the destroyer Natsushio on 20 October 1941. He was the ship's second commanding officer. He had already commanded the destroyer Nenohi, had served as chief of staff of Destroyer Squadron 1, and came to Natsushio from the Navy Ministry personnel bureau.
Natsushio was a Kagero-class destroyer built at the Fujinagata yard in Osaka. Her keel had been laid in December 1937, she was launched in February 1939, and she entered service on 31 August 1940. Under Nagai she belonged to Destroyer Division 15, with Oyashio, Hayashio, and Kuroshio, in Destroyer Squadron 2 of the Second Fleet. On 25 October 1941 the division commander, Captain Sato Torajiro, shifted his flag from Hayashio to Natsushio, so Nagai's ship carried the division staff as well as her own company.
In the last days of November 1941 the squadron left home waters and reached Palau on 1 December, a staging point for the opening offensive in the south. From 6 to 8 December Natsushio screened the light carrier Ryujo while that ship's aircraft struck Davao in the southern Philippines. On 10 and 11 December she and Hayashio covered the minelayer Yaeyama while mines were laid in Surigao Strait. Through the rest of December she stood by the landings at Legazpi, Davao, and Jolo.
In January 1942 the division escorted invasion groups into the Netherlands East Indies, including the landings at Menado, Kendari, and Ambon. During the move against Makassar, on the night of 8 February, the American submarine S-37 hit Natsushio with a torpedo. The blast killed several of the crew and left the destroyer unable to steam. In the early hours of 9 February Kuroshio took off the survivors, Nagai among them, and tried to tow the damaged ship clear. The weather worsened, the tow was slipped, and Natsushio sank about twenty-two miles south of Makassar. She was the first Japanese destroyer lost to an American submarine in the war, and the first of her class to go down.
On 14 February 1942 Nagai was released from command of the lost ship and assigned to the Kure Naval District. Natsushio was removed from the Navy list on 28 February, and the paperwork of her loss was closed at Kure that spring. Nagai was later promoted to captain and appointed chief of staff of Destroyer Squadron 4.