The Agano-class cruisers (阿賀野型軽巡洋艦) were designed as a new generation of about 5,000 ton displacement ships to lead destroyer and submarine squadrons. They were conceived in the 1930s as a replacement for the aging Tenryū, Kuma and Nagara classes. Larger than these previous light cruisers, the Agano-class vessels were fast, but with little protection, and were under-gunned for their size.
Unlike the previous light cruiser classes, their main armament was the 152 mm (6 inch) gun that was used by the Kongō-class battlecruisers, and some of these weapons having been removed from the Fusō and Kongō classes during their modernizations in the early and late 1930s, respectively.
They were also only the first Japanese warships to be equipped with bulbous bows, each equipped with a single catapult forward of the main mast with carrying capacity of two seaplanes.