三川軍一
On 16 August, a Japanese convoy of three slow transport ships loaded with 1,411 soldiers from the 28th "Ichiki" Infantry Regiment, as well as several hundred naval troops from the 5th Yokosuka Special Naval Landing Force (SNLF), departed the major Japanese base at Truk Lagoon (Chuuk) and headed towards Guadalcanal. The transports were guarded by the light cruiser , eight destroyers, and four patrol boats, with the escort force commanded by Rear Admiral Raizō Tanaka, who flew his flag in "Jintsū". Also departing from Rabaul to help protect the convoy was a "close cover force" of four heavy cruisers from the 8th Fleet, commanded by Vice Admiral Gunichi Mikawa. These were the same, relatively old, heavy cruisers that had defeated an Allied naval surface force in the earlier Battle of Savo Island, less the , which had been sunk by an American submarine. Tanaka planned to land the troops from his convoy on Guadalcanal on 24 August.