The Katori-class cruisers (香取型練習巡洋艦) were originally ordered by the Imperial Japanese Navy to serve as training ships in the 1937 and 1939 Supplementary Naval budgets. During the Pacific War, they were used as administrative flagships for various fleets, such as submarine command and control, and to command escort squadrons. The ships were upgraded as the war progressed with additional anti-aircraft guns and depth charges.
They are purpose-designed to replace the aging armored cruisers in the officer training role, and as such differed from other IJN cruisers in several aspects. Built to commercial standards to minimize cost, the Katori-class had a lower length-to-beam ratio than was usual for cruisers, giving the ships greater initial stability for trainees unfamiliar with lives at sea. Unusually for IJN ships, the Katori-class had mixed steam turbine/diesel propulsion, intended to maximize the ships' instructional value rather than speed: even at a combined 8000 shp the maximum speed was only 18 knots, too slow for conventional cruiser duties.