Japan finished WWI with a pretty strong Navy. Not like those of Great Britain or even Imperial Germany, but one that met their needs. Like all navies, it was important to continue to build newer ships to replace the older ones and to modernize those that were still in the fleet to meet changing situations. When Japan entered WWII, it had a pretty strong navy in terms of surface forces.

In one area where Japan differed tactically from other naval forces is in the use of light cruisers. While other nations had them as part of the screening force for their main fleet, the Japanese used light cruisers as flotilla leaders for destroyer or submarine flotillas. This was something rather foreign to other navies of the world, but then the Japanese had and still have a bit different way of looking at things and it was decided that these light cruisers would hold the flotilla staff, so needed a larger ship.

However, Japanese destroyer construction and development outpaced most of Japan's light cruisers. Not only were the destroyers faster than the lead ship, but they were often equally armed. This put a bit of a strain on things until newer ships with greater speed and armor were built to replace them. Once replaced, Japan used those ships as fast transports, sub hunters or fleet protection.

Throughout the war, Japan's light cruiser force played catch up in terms of equipment such as radars and they were always considered by other nations to have inadequate anti-air protection. It is not all that surprising that close to half lost were lost to air action. The most lost were to submarines while only two were lost during surface action. Two ships survived the war in good enough condition to help repatriate Japanese soldiers before they were scrapped.

This book in the New Vanguard series looks at the eight major classes of Japanese heavy cruisers which included the Tenryu, Nagara, Yubari, the one off Oyodo and even the Katori class training cruisers. Each class is provided a basic history of the ships as well as the design and modifications made to them as time progressed. There are a superb number of period photos of each type as well as cutaways and the excellent artwork of Paul Wright to help us visualize what these ships were like in action.