Mikuma (三隈, namesake: Mikuma River) was the second of the four Mogami-class heavy cruisers. The class was designed as a heavy cruiser from the outset but, due to restrictions imposed by the London Naval Treaty, the Imperial Japanese Navy mounted turrets with 155 mm guns to pass it off as a light cruiser, with the intention of replacing them with 203 mm guns later on.

Mikuma was laid down on 24 December 1931 at Mitsubishi's Nagasaki shipyard, launched on 31 May 1934, and commissioned on 29 August 1935. After four years as a light cruiser, Mikuma and her sister ships were refitted in 1939, replacing the 155 mm turrets with 203 mm ones as per the original design. Mikuma's former 155 mm turrets would later be fitted to the battleship Yamato, which was still under construction at that time.

On the eve of the Pacific War on 7 December 1941, Mikuma was assigned to Cruiser Division 7 and was deployed to cover the invasion of British Malaya and southern Thailand, and later the Dutch East Indies. On the night of 28 February 1942, Mikuma, along with the light cruiser Natori and five other destroyers, participated in the Battle of Sunda Strait against USS Houston (CA-30) and HMAS Perth. Mikuma and her allies managed to encircle the Allied cruisers and sank both of them, with Mikuma only suffering minor damage from Houston's return fire. Following the victory, Mikuma and Division 7 were deployed in the Indian Ocean raids from 31 March to 10 April.

Mikuma and Division 7 would later participate in the Battle of Midway. On 5 June, after Mikuma's sister ship Kumano spotted the American submarine USS Tambor (SS-198), Division 7 attempted to retreat. Due to the ensuing chaos and pitch darkness, Mikuma was accidentally rammed by her sister ship Mogami, resulting in an oil leak and leaving both lagging behind the rest of the fleet. When they were spotted that morning, the Americans mistakenly identified them as battleships. As a result, both cruisers were subjected to intense bombing. On 6 June, Mogami and Mikuma were targeted by air groups from USS Hornet (CV-8). While Mogami managed to escape, Mikuma was struck by four bombs from SBD Dauntless aircraft, causing her forward magazine and torpedo storage to detonate, resulting in fatal damage that sank the ship. Out of 951 crew members, only 188 survived the sinking.

Introduced in Update 1.97 "Viking Fury", Mikuma is largely similar to her sister ship Suzuya, with a slightly higher crew count. As the Mogami-class was built around high top speed and firepower, Mikuma's lighter armament results in improved mobility while retaining the same protection as her heavier-armed sister Mogami. However, Mikuma retains the typical weaknesses of Japanese cruisers, namely weak turret protection and lacklustre anti-air armament.