The Isuzu (五十鈴, namesake: Isuzu river) was the second of the six Nagara-class light cruisers. First ordered in 1920, the Nagara-class was an improved version of the Kuma-class light cruiser, being designed to fulfil the same role as a destroyer leader. As for the Isuzu, after being deployed for the Invasion of Hong Kong in December 1941, she served during various island-hopping campaigns in the Pacific, most notably during the second Battle of Guadalcanal. After sustained damage from American dive bombers in December 1943, Isuzu was withdrawn back to Japan. Given the increasing threat of the American carrier fleets and the obsolescence of Isuzu herself, she was converted into an anti-air cruiser by replacing her main armament of seven 140 mm 3rd year cannons with three dual-mount 127 mm Type 89 heavy anti-air cannons as well as a staggering fifty 25 mm Type 96 anti-air guns. Under this configuration, Isuzu provided air cover for her allies during the Battle of Leyte Gulf on October 1944. However, the combination of the overwhelming air superiority of the US Navy along with the inadequate range of the Type 96 guns resulted in the two ships that the Isuzu escorted, the light aircraft carriers Chitose and Chiyoda, being sunk. Isuzu met her end on 7 April 1945 off the coast of Sumbawa island by a combined torpedo attack of American submarines USS Charr (SS-328) and USS Gabilan (SS-252), resulting in 190 deaths with 450 survivors.
Introduced in Update "Ixwa Strike", Isuzu is in her 1944 refit, with the sole purpose of acting as a floating anti-aircraft platform. As a result, Isuzu has unparalleled anti-air capabilities for her rank in exchange for anti-ship firepower. Because of the removal of cruiser-calibre guns, the Isuzu is very fast and agile for a cruiser. However, due to her age and the aforementioned conversion, she is ill-suited for fighting a proper cruiser due to her poor survivability resulting from the crew compartments being placed on the unarmoured deck and her 127 mm guns lacking any armour-piercing shells. Gameplay-wise, the Isuzu is best described as an oversized destroyer, capable of providing fire support and hit-and-run using her superior speed and a set of Long Lance torpedoes, but unable to hold on her own without proper support.