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.

[3] Naval architect Vice Admiral Yuzuru Hiraga was able to keep the design from becoming dangerously top-heavy in its early years by continually rejecting demands from the IJN general staff for additional equipment to the upper decks.

[4] Nachi’s main battery was ten 20 cm/50 3rd Year Type naval guns, the heaviest armament of any heavy cruiser in the world at the time, mounted in five twin turrets.

Due to a political decision, the partially completed cruiser was sent to Yokosuka for the coronation naval review for Emperor Hirohito on 4 December.

Emperor Hirohito visited the completed vessel at Kobe for a cruise on the Inland Sea on 28–29 May as part of his tour of the Kansai region of Japan to encourage domestic industrial production.

During a naval review off Kobe on 26 October 1930, stack gases caused problems on the bridge, resulting in a lengthening of the forward smokestack by 2.0 m.[4] During the First Shanghai Incident of February 1932, the cruisers escorted the transports conveying elements of the Imperial Japanese Army (IJA) to the continent.

With the start of the Second Sino-Japanese War in 1937, Nachi transported the headquarters elements of the IJA's 3rd Division and 6th Infantry Regiment from Nagoya to China on 20 August, as part of a large combat force consisting of six cruisers and eight destroyers.

[5] In December 1937, Nachi underwent her second modernization program at Sasebo Naval Arsenal, doubling the number of torpedoes to 16, adding another eight Type 96 25-mm antiaircraft guns and bulges to the hull to improve stability.

Sentai-5 was commanded by Rear Admiral Takeo Takagi, and deployed from Palau to provide cover for the landings of Japanese forces under "Operation M" — the invasion of the southern Philippine Islands.

In the Battle of the Java Sea, Nachi, Haguro, and Jintsū participated in the destruction of the last remaining Allied fleet units in the Netherlands East Indies.

For her part of the engagement, Nachi damaged the heavy cruiser USS Houston with a pair of 8-inch (203 mm) shell hits at distances beyond 22,000 yards, one passing through the bow, and the other punching through the aft section.

The destroyer USS Pope, who was accompanying the two British ships, initially escaped the melee only to be caught and crippled about two hours later by planes from the Japanese light carrier Ryujo, and finished off by Myōkō and Ashigara.

[5] While escorting another convoy towards Attu on 26 March, Nachi spotted an American force consisting of the cruisers USS Richmond and Salt Lake City and destroyers Bailey, Dale, Monaghan, and Coghlan.

During the Battle of Leyte Gulf from 24 October, Nachi and Ashigara were part of Vice Admiral Shoji Nishimura’s force, which included the battleships Yamashiro, Fuso and the cruiser Mogami.

The original wartime caption of a picture taken of the sinking Nachi by Lexington aircraft reads, Note by target coordinator: We circled down to 20 feet to make sure there were absolutely no survivors.

In April and May 1945, divers from USS Chanticleer made 296 dives on the wreck, salvaging radar equipment, code books, and maps of Japanese fortifications on Luzon and other documents.