Nachi (那智) was the second vessel completed of the four-member Myōkō class of heavy cruisers of the Imperial Japanese Navy (IJN), which were active in World War II. The other ships of the class were Myōkō, Ashigara, and Haguro. She was named after a mountain in Wakayama Prefecture.
The Mogami class (最上型) was a ship class of four cruisers built for the Imperial Japanese Navy (IJN) during the 1930s. They were initially classified as light cruisers under the weight and armament restrictions of the London Naval Treaty. After Japan abrogated that agreement, all four ships were rearmed with larger guns and reclassified as heavy cruisers. All participated in World War II and were sunk.
Tenryū was the lead ship in the two-ship Tenryū class of light cruisers of the Imperial Japanese Navy. Tenryū was named after the Tenryū River in Nagano and Shizuoka prefectures.
Tatsuta (龍田) was the second ship in the two ship Tenryū class of light cruisers in the Imperial Japanese Navy (IJN). She was named after the Tatsuta River in Nara Prefecture, Japan.
Mogami (最上) was the lead ship in the four-vessel Mogami class of heavy cruisers in the Imperial Japanese Navy. She was named after the Mogami River in Tōhoku region of Japan. The Mogami-class ships were constructed as "light cruisers" with five triple 155-millimetre (6.1 in) dual purpose guns. They were exceptionally large for light cruisers, and the barbettes for the main battery were designed for quick refitting with twin 8-inch (203 mm) guns. In 1937 all four ships were "converted" to heavy cruisers in this fashion. Mogami served in numerous combat engagements in World War II, until she was sunk at the Battle of Leyte Gulf in October 1944.
Yura (由良) was the fourth of the six ships completed in the Nagara class of light cruisers for the Imperial Japanese Navy (IJN), and like other vessels of her class, she was intended for use as the flagship of a destroyer flotilla. She served in the early stages of World War II.
Tokitsukaze was the tenth vessel to be commissioned in the 19-vessel Kagerō-class destroyers built for the Imperial Japanese Navy in the late-1930s under the Circle Three Supplementary Naval Expansion Program.
Yūgure was the sixth and last Hatsuharu-class destroyer, built for the Imperial Japanese Navy under the Circle One Program. Three were laid down in JFY 1931 and the next three in JFY 1933.
Ariake was the fifth of six Hatsuharu-class destroyers, built for the Imperial Japanese Navy under the Circle One Program. Three were laid down in JFY 1931 and the next three in JFY 1933.
Nenohi was the second of six Hatsuharu-class destroyers, built for the Imperial Japanese Navy under the Circle One Program. Three were laid down in JFY 1931 and the next three in JFY 1933. The remaining six ships in the plan were built as the Shiratsuyu class.
Wakaba was the third of six Hatsuharu-class destroyers, built for the Imperial Japanese Navy under the Circle One Program. Three were laid down in JFY 1931 and the next three in JFY 1933. The remaining six ships in the plan were built as the Shiratsuyu class.
The two Tone-class cruisers were the last heavy cruisers completed for the Imperial Japanese Navy. The Tone-class cruisers were originally envisaged as the 5th and 6th vessels in the Mogami class. However, by the time construction began, serious weaknesses in the Mogami-class hull design had become clear following the Fourth Fleet incident in 1935. As Japan no longer was obligated to abide by the limitations of the London Naval Treaty, a new design was created and new means of construction were utilized. Although the external dimensions were close to the Mogami class, the design was quite different, with all the main battery of guns placed forward of the bridge, reserving the entire stern area as a large seaplane operations deck. Unlike the U.S. Navy, the Japanese did not have a dual role attack/scout aircraft, nor did they assign any of their carrier aircraft to a reconnaissance role. Little emphasis was placed on this aspect of carrier warfare. Instead the Japanese reserved all of their carrier aircraft for attack roles. Reconnaissance then was relegated to the float planes carried by cruisers. The Tone and the Chikuma were intended to provide the long range reconnaissance needed for Japan's carrier Air Fleets.
The Hatsuharu-class destroyers were a class of Imperial Japanese Navy destroyers in the service before and during World War II. The final two vessels in the class, completed after modifications to the design, are sometimes considered a separate "Ariake class".
Vice Admiral Baron Yuzuru Hiraga was a career naval officer in the Imperial Japanese Navy, Doctor of Engineering and head of the engineering school of Tokyo Imperial University and a leading Japanese naval architect in the 1910s and 1920s, responsible for designing a number of famous warships, many of which would later see action during World War II. He participated in establishing the Chiba Institute of Technology from 1941.
The Kamikaze-class destroyers were a class of nine destroyers of the Imperial Japanese Navy. Some authors consider the Nokaze, Kamikaze and Mutsuki classes to be extensions of the Minekaze-class destroyers, and the Kamikaze class is sometimes referred to as the "Kiyokaze class" to distinguish it from the earlier World War I-era destroyer class of the same name. Obsolete by the beginning of the Pacific War, the Kamikazes were relegated to mostly secondary roles. Most ultimately were lost to U.S. submarines.
The Ōtori-class torpedo boat were a class of eight fast torpedo boats of the Imperial Japanese Navy built before and operated during World War II.
Japanese destroyers of World War II included some of the most formidable destroyers of their day. This came as a surprise to the Allies, who had generally underestimated Japanese technical capabilities. The Japanese had reassessed their naval needs in the mid-1920s and, placing an emphasis on ship and weapons technology and night-fighting expertise, developed a completely new destroyer design. Subsequent development from one destroyer class to the next was not, however, a smooth progression. Aside from the usual changes arising from experience, serious design faults also came to light and naval treaties imposed restrictions. As a result, the early "Special Type" destroyers required significant changes and the specifications of subsequent classes was reduced in one way or another. Naval treaties were later abrogated in 1937 and so destroyer development continued without regard to limits.
The Japanese destroyer Mochizuki was one of twelve Mutsuki-class destroyers, built for the Imperial Japanese Navy (IJN) during the 1920s. During the Pacific War, she participated in the Battle of Wake Island in December 1941 and the occupations of New Guinea and the Solomon Islands in early 1942.
The Japanese destroyer Yayoi was one of twelve Mutsuki-class destroyers built for the Imperial Japanese Navy (IJN) during the 1920s. During the Pacific War, she participated in the Battle of Wake Island in December 1941 and the occupations of New Guinea and the Solomon Islands in early 1942.
The Chidori-class torpedo boat was an Imperial Japanese Navy class of torpedo boats that were built before and served during the Second World War. The design initially proved to have too much armament for its small displacement, and the capsizing of Tomozuru (友鶴) shortly after completion in heavy weather resulted in a scandal which called into question the basic design of many Japanese warships of the time. After extensive modification, the class became satisfactory sea-boats and saw service in the Battle of the Philippines and the Dutch East Indies campaign as escorts and continued in that role for the rest of the war. Three were sunk during the war and the fourth was seized by the British at Hong Kong after the end of the war, where it was scrapped later.
Empire of Japan 
