回天
The "Kaiten" (回天, literally "heaven shaker"), was a large manned [[torpedo]] based of the infamous Type 93 "Long Lance" employed by the [[Imperial Japanese Navy]] for suicide attacks. It is similar to kamikaze pilots, as both were conceptualized during the late stage of [[World War II]] in a desperate attempt to slow down Allied force's advance to the Japanese home island.

It was of questionable use and exceptionally dangerous to both those handling them and the pilots; around 200 kaiten trainees, mechanics and hosts (the kaiten were fired from other ships or submarines) were killed while attempting to employ kaitens. Meanwhile, only 3 ships were sunk by the weapon.
kaiten (weapon)