Background

• In 1920, the IJN made Eight-eight fleet final plan, and they were going to have eight battleships and eight battle cruisers. However, they did not forget Hatsuse
  Japanese battleship Hatsuse
  |-External links:**...
  
   and Yashima
  Japanese battleship Yashima
  |-External links:** The New York Times, June 2, 1905....
  
   in the Russo-Japanese War
  Russo-Japanese War
  The Russo-Japanese War was "the first great war of the 20th century." It grew out of rival imperial ambitions of the Russian Empire and Japanese Empire over Manchuria and Korea...
  
  . The IJN was afraid that their new battleships was lost once again with an enemy's naval mine.
• In the IJN, their destroyers undertook minesweeping operations. However, the IJN gave their destroyers a duty of minelayer. Therefore, they wanted the new minesweeper which could follow their new battleships.
• The IJN demanded that they cleaned a route of the Combined Fleet
  Combined Fleet
  The was the main ocean-going component of the Imperial Japanese Navy. The Combined Fleet was not a standing force, but a temporary force formed for the duration of a conflict or major naval maneuvers from various units normally under separate commands in peacetime....
  
   by the No.1-class. Therefore, they gave No.1-class their destroyer and an equal weapons and 20 kt speed. Furthermore, the IJN more added a minelayer facilities for the No.1-class.

No.1 class

• Project number I1. 4 vessels were built in 1922-1925. No.4 was behind with the laid down by the Washington Naval Treaty
  Washington Naval Treaty
  The Washington Naval Treaty, also known as the Five-Power Treaty, was an attempt to cap and limit, and "prevent 'further' costly escalation" of the naval arms race that had begun after World War I between various International powers, each of which had significant naval fleets. The treaty was...
  
  .

  Ship	Builder	Laid down	Launched	Completed	Fate
  No.1	Harima Zōsen	10 May 1922	6 March 1923	30 June 1923	Sunk by air raid at Yamada Bay Yamada, Iwate is a town located in Shimohei District, Iwate, Japan.As of 2003, the town has an estimated population of 20,413 and a population density of 77.49 persons per km². The total area is 263.44 km²....  on 10 August 1945. Decommissioned on 15 September 1945.
  No.2	Mitsui, Tama Shipyard	13 April 1922	17 March 1923	30 June 1923	Sunk by friendly torpedo by Mogami or Mikuma Japanese cruiser Mikuma was the second vessel in the four-vessel Mogami-class of heavy cruisers in the Imperial Japanese Navy. It was named after the Mikuma river in Oita prefecture, Japan.-Background:...  at Bantam Bay during the Battle of Sunda Strait Battle of Sunda Strait The Battle of Sunda Strait was a naval battle which occurred during World War II. On the night of 28 February – 1 March 1942, the Australian light cruiser and the American heavy cruiser faced a major Imperial Japanese Navy task force. After a fierce battle of several hours duration, both Allied...  on 1 March 1942. Decommissioned on 30 November 1945.
  No.3	Ōsaka Iron Works		29 March 1923	30 June 1923	Sunk by USS Parche USS Parche (SS-384) The first USS Parche was a United States Navy submarine. She bore the name of a butterfly fish, Chaetodon capistratus....  at Ōfunato Bay Ofunato, Iwate is a coastal city located in Iwate, Japan.It was founded on April 1, 1952.On November 15, 2001, the town of Sanriku, from Kesen District, was merged into Ōfunato....  on 9 April 1945. Decommissioned on 10 May 1945.
  No.4	Sasebo Naval Arsenal	1 December 1923	24 April 1924	29 April 1925	Scuttled by Royal Navy Royal Navy The Royal Navy is the naval warfare service branch of the British Armed Forces. Founded in the 16th century, it is the oldest service branch and is known as the Senior Service...  at Singapore Singapore Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...  on 11 July 1946. Decommissioned on 10 August 1946.

No.5 class

• Project number I2. 2 vessels were built in 1928-1929. Improved model of the No.1-class. About their appearance, foremast was changed to tripod type.

  Ship	Builder	Laid down	Launched	Completed	Fate
  No.5	Mitsui, Tama Shipyard	25 March 1928	30 Octpber 1928	25 February 1929	Sunk by HMS Terrapin HMS Terrapin (P323) HMS Terrapin was a British submarine of the third group of the T class. She was built as P323 by Vickers Armstrong, Barrow and Bellis and Morcom Ltd, and launched on 31 August 1943...  at Strait of Malacca Strait of Malacca The Strait of Malacca is a narrow, stretch of water between the Malay Peninsula and the Indonesian island of Sumatra. It is named after the Malacca Sultanate that ruled over the archipelago between 1414 to 1511.-Extent:...  33°44′N 99°50′E on 4 November 1944. Decommissioned on 10 March 1945.
  No.6	Ōsaka Iron Works	10 March 1928	29 Octpber 1928	25 February 1929	Sunk by air raid off Kuching Kuching Kuching , officially the City of Kuching, and formerly the City of Sarawak, is the capital and most populous city of the East Malaysian state of Sarawak. It is the largest city on the island of Borneo, and the fourth largest city in Malaysia.... 01°34′N 110°21′E on 26 December 1941. Decommissioned on 10 January 1942.