[1][2][7] When the news of Allied landings on Guadalcanal and Tulagi reached the 8th Fleet headquarters on August 7, Mikawa promptly decided to make a night-time counter-attack with his available surface naval forces, despite the presence of American carriers.

Nevertheless, they failed to follow through and destroy the lightly protected American transports that were in the process of landing critical supplies for the Allied troops on the ground.

[10] On 28 August 1942, the 8th Fleet also created the R-Area Air Force, which exclusively operated seaplanes in order to compensate for the lack of land bases in the Solomon Islands area.

[5][11] Since regular resupply runs by destroyers only could not deliver heavy equipment (such as artillery) to the Imperial Japanese Army (IJA) on Guadalcanal, the 8th Fleet's Reinforcement Unit started using seaplane tenders Chitose and Nisshin as high-speed transports.

To cover the unloading of supplies by the convoy on 11 October, the 8th Fleet assigned CruDiv6 with heavy cruisers Aoba, Kinugasa and Furutaka and two destroyers under Rear Admiral Gotō to bombard the Allied position on Guadalcanal.

[12][13] Another major resupply run was conducted on the night of 14/15 October by Nisshin, while Vice Admiral Mikawa with Chōkai and Kinugasa shelled Allied position on Guadalcanal to cover the cargo unloading process.

In the early morning of November 14, Maya and Suzuya were detached under Rear Admiral Shōji Nishimura to conduct a bombardment of the Allied position on Guadalcanal, before rendezvousing with Mikawa and the rest of the force after sunrise south of New Georgia.

[18][19] The 8th Fleet subsequently played a major role in Operation KE, the successful withdrawal of army forces from Guadalcanal during the first week of February 1943.