While I knew that Japan was driven to such desperation during World War II that they resorted to Kamikaze, I had no idea that a similar suicide unit existed for navy as well. The unit was called ‘Kai Ten’ and basically used torpedos modified to accomodate human ‘drivers’ who would ram them into the enemy ship.
I came across a fictional autobiographical account of a Kai Ten ‘driver’ in David Mitchell’s Number 9 Dream. Each paragraph of that account sent a chill down my spine. And to think that someone lived through it…
Wikipedia has more if you have the stomach for it.
As an aside, the Kanji for Kai Ten (the phrase roughly means ‘the turn toward heaven’) is 回天. While I am not sure I can explain 回, it’s quite easy to logically explain the origin of 天. The Kanji for big (huge, enormous) is 大. It is simplification of drawing of a man with his arms outstretched. (How big? This “大” Big). Add a bar or ‘roof’ on top of it and you get Kanji for ‘big-roof’ or (figuratively speaking) sky though it’s used more in the sense of ‘heaven’.