Natsushima-class minelayer (1933)
The  was a class of minelayers of the Imperial Japanese Navy (IJN), serving during and after the 1930s through World War II. Their design was based on the Tsubame-class, but with increased armament. Ships in class

Natsushima-class
Project number H5. 3 vessels were planned under the Maru 1 Programme, however, 3rd ship Sarushima was used to diesel engine experiment ship. 24 December 1931: Laid down at Tōkyō Ishikawajima Zōsen. 24 March 1933: Launched. 31 July 1933: Completed. In 1934: Rebuilding after the Tomozuru Incident. In 1938: Sortie for the Second Sino-Japanese War. 1941-1943: Sortie for the naval mine laying at Japan Mainland. 10 December 1943: Dispatched to southeast area. 22 February 1944: Sunk by USS Stanly, USS Charles Ausburne and USS Dyson off Kavieng . 30 April 1944: Removed from naval ship list. 19 January 1933: Laid down at Harima Zōsen. 26 March 1934: Launched. 20 September 1934: Completed. In 1938: Sortie for the Second Sino-Japanese War. 1941-1943: Sortie for the naval mine laying at Japan Mainland and convoy escort operations at East China Sea. 31 December 1943: Dispatched to southeast area. 1 April 1944: Sunk by air raid at Rabaul. 10 April 1944: Removed from naval ship list. Sarushima-class
Project number H5B. She was built as diesel engine experiment ship. Her results were made use of in the Sokuten-class. 28 March 1933: Laid down at Mitsubishi, Yokohama shipyard. 16 December 1933: Launched. 20 July 1934: Completed. In 1938: Sortie for the Second Sino-Japanese War. 1941-1944: Sortie for the naval mine laying and convoy escort operations at Japan Mainland. 4 July 1944: Sunk by air raid off Otōto-jima. 10 September 1944: Removed from naval ship list. Photos

Bibliography
Ships of the World special issue Vol.45, "Escort Vessels of the Imperial Japanese Navy", , (Tokyo, Japan), 1996. The Maru Special, Japanese Naval Vessels No.47, "Japanese naval mine warfare crafts",  (Tokyo, Japan), 1981.