Ships
- IJN Ryujo Captain from 1 December 1937 · Relieved on 15 December 1938
- IJN Kaga Captain from 15 September 1941
Jisaku Okada was born in Kanazawa, Ishikawa Prefecture, on 13 August 1893. He entered the Imperial Japanese Navy in 1914 and spent his career in naval aviation, moving from shore air stations to shipboard air groups as Japan built a carrier fleet.
He served at Kasumigaura, Omura, and Yokosuka as a division officer, a flight leader, and an instructor, and the navy sent him abroad to study aviation in Europe and the United States. In December 1926 he was promoted to lieutenant commander. In November 1932 he became flight officer of the carrier Kaga, responsible for her embarked aircraft. In the service he was known for his work on bombing methods and for his skill as a bombardier.
He later commanded the 23rd Naval Air Group, the seaplane tender Notoro, and the light carrier Ryujo. On 15 September 1941 he returned to Kaga as captain, relieving his classmate, Captain Yamada Sadayoshi. The ship was in Carrier Division 1 of Vice Admiral Chuichi Nagumo's First Air Fleet, and she spent the autumn working up for war.
In December 1941 Kaga sailed with the carrier force that attacked Pearl Harbor. Through the opening months of 1942 Okada kept her with the fast carriers in the South Pacific and the Dutch East Indies, including the air strike on Darwin in February. That same month she tore her hull on a reef near Palau. Repairs at Sasebo kept her out of the April raid into the Indian Ocean, and she rejoined the fleet in time for the move against Midway.
Kaga left Japan in late May 1942 with Akagi, Soryu, and Hiryu. On the morning of 4 June her aircraft bombed Midway Island. While the Japanese carriers were recovering and rearming planes, American dive bombers found Nagumo's ships with little warning.
Several bombs from aircraft of the carrier Enterprise hit Kaga. One explosion wrecked the bridge. Okada was killed there, together with much of his staff, including the executive officer, the navigator, and the paymaster. Commander Takahisa Amagai, the air officer and the senior officer left, took charge of the ship. Fueled and armed aircraft in the hangars turned the hits into a chain of fires. Destroyers took off the men who could get clear, and Kaga was lost that day, with about eight hundred of her crew. Okada was forty-eight. The navy promoted him to rear admiral after his death.