This article may require cleanup to meet Wikipedia's quality standards . No cleanup reason has been specified. Please help improve this article if you can. This article does not cite any references or sources . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . , often abbreviated to 特攻隊 tokkōtai), also called shimbu-tai, were specialized units of the Imperial Japanese Navy and Imperial Japanese Army normally used for suicide missions. They included kamikaze bombers, Fukuryu ("Crouching Dragon", suicide scuba divers), and several types of suicide ships and submarines. This section does not cite any references or sources . Please help improve this section by adding citations to reliable sources . Unsourced material may be challenged and removed . , variously translated as "Change the World", "Returning to Heaven" or "Heaven-shaker") was a torpedo modified as a suicide weapon , and used by the Imperial Japanese Navy in the final stages of World War II.Early designs allowed for the pilot to escape after the final acceleration towards the target, although whether this could have been done successfully is doubtful. There is no record of japanese rocket aircraft any pilot attempting to escape or intending to do so, and this provision was dropped from later production kaitens. The inventor of the Kaiten, Lt. Hiroshi Kuroki was lost during one of the first training missions. When the sub was raised, a note written during his final minutes before death was found, sending his respects to his family and detailing the cause of the accident and how to repair the defect. , "Sea Dragon") was a class of kamikaze midget submarines of the Imperial Japanese Navy , designed in 1943-1944, and produced from the beginning of 1945. These submarines were meant to meet the invading American Naval forces upon their anticipated approach of Tokyo.These submarines had a two-man crew and were fitted with an internal warhead for suicide missions. Over 760 of these submarines were planned, and by August 1945, 200 had been manufactured, most of them at the Yokosuka shipyard. , "Crouching dragons") were a part of the Special Attack Units prepared to resist the invasion of the Home islands by Allied forces. They were armed with a mine containing 15 kg (33 lb) of explosive, fitted to a 5 m (16 ft) bamboo pole. They would dive and stick the pole into the hull of an enemy ship, destroying themselves in the process. They were equipped with a diving jacket and trousers, diving shoes, and a diving helmet fixed by four bolts. They were typically weighed down with 9 kg (20 lb) of lead, and had two bottles of compressed air at 150 bars. They were expected to be able to walk at a depth of 5 to 7 m (16 to 23 ft), for about six hours. This new weapon is only known to have been used a few times operationally:.