At the time of the attack on Pearl Harbor in December 1941, "Okinoshima" was serving as flagship for Admiral Kiyohide Shima in Operation "Gi" (the invasion of the Gilbert Islands) and had deployed from Jaluit with a Special Naval Landing Force (SNLF) embarked. From 9–10 December, "Okinoshima" supported the Japanese landings on Makin and on Tarawa, and on 24 December, the seizure of Abaiang. "Okinoshima" was at Truk on 1 January 1942.