Japanese Swords in Fiction

Japanese Swords In Fiction

Many legends surround Japanese swords, the most frequent being that the blades are folded an immense number of times, gaining magical properties in the meantime. While blades folded hundreds, thousands, or even millions of times are encountered in fiction, there is no record of real blades being folded more than around 20 times. With each fold made by the maker, every internal layer is also folded, and so the total number of layers in a sword blade is doubled at each fold; since the thickness of a katana blade is less than 230 iron atoms, going beyond 20 folds no longer adds meaningfully to the number of layers in the blade. Folding a blade only 10 times will therefore create 1024 layers; 20 times will create 1,048,576 layers.

Furthermore, while heating and folding serves to even out the distribution of carbon throughout the blade, a small amount of carbon is also 'burnt out' of the steel in this process; repeated folding will eventually remove most of the carbon, turning the material into softer iron and reducing its ability to hold a sharp edge. This can be combated with carburization, though it does not produce even carbon distribution, partially defeating the purpose of folding.

Some swords were reputed to reflect their creators' personalities. Those made by Muramasa had a reputation for violence and bloodshed, while those made by Masamune were considered weapons of peace. A popular legend tells of what happens when two swords made by Muramasa and Masamune were held in a stream carrying fallen lotus petals: while those leaves touching the Muramasa blade were cut in two, those coming towards the Masamune suddenly changed course and went around the blade without touching it.

Kusanagi (probably a tsurugi, a type of Bronze Age sword which precedes the Katana by centuries) is the most famous legendary sword in Japanese mythology, involved in several folk stories. Along with the Jewel and the Mirror, it was one of the three godly treasures of Japan. A common misconception is that Katanas magically sprung into existence in Japan, utterly isolated from the mainland. The technique of folding steel came from the manufacture of the Dao in China, and contact with the mainland would affect how the katana evolved through the centuries. The katana design itself was developed over hundreds of years and the katana design was a development of the Tatchi.