An ancient craft dating back hundreds of years
While there is no set formula to re-create the Koto swords Watanabe refuses to take any shortcuts and use any modern technology available, because for him the only way to maintain the tradition of sword making is to ensure the craft survives in its purest form.
The history of the Samurai sword is divided into four periods – Koto (Pre 1596), Shinto /Shinshinto (1597 to 1876), Gendai (1877 to the end of world war II), and Shinsaku (modern).
The first Japanese swords were variations of the Chinese Jian (called Chokuto)- a straight, double edged iron blade. However, sometime during the early Heian period, around 700AD, the first uniquely Japanese swords that were the forerunners of the modern Katana (sword) began to evolve - this is the Koto sword which Watanabe is trying to craft.
Initially, the first Japanese swords were curved at the tang (end of the blade) only, but by the end of the 10th century fully curved swords were commonplace. It was during this time that Japan began to abandon cultural ties with China. Its society stabilized into class divisions with the military guards of the capital and the gentlemen of the provinces becoming the first Samurai.
No one can pinpoint exactly when the first true Samurai swords were crafted, as written records of Samurai sword history are few and far between. Japanese myths identify the turning point of Samurai sword history with a smith called Amakuni.
Crafting the traditional Katana sword
The traditional Samurai sword is made from specialist Japanese steel, Tamahagane, which is made up of combinations of hard, high carbon steel, and tough, low carbon steel. The idea is that the high carbon steel is harder and able to form the shape of the sword, while the low carbon steel is more flexible. Essentially a harder outer jacket of steel is wrapped around a softer inner core of steel. Having hard carbon allows the sword to absorb impact and be more malleable, becoming blunt but not breaking during any form of combat.
The process of crafting a traditional sword needs devilish attention to detail that can take a matter of months. Even the slightest blemish means the sword must be scrapped. The metal can be folded up to 200 times and is eventually covered in clay during a process called quenching that gives the sword its curvature and also hardens the blade.
The Koto sword is the earliest form of Samurai sword, and there is no clear blueprint to follow – with Watanabe using his own instincts to craft the original sword.
When Watanabe started crafting swords in his youth, his family were opposed to his apprenticeship and for the last 40 years he has been perfecting his skills. It is only in the last 5 years he has achieved successful results – and he is eager to keep the dying craft alive. “It is my duty to build up a disciple better than me. Otherwise the tradition will wear thin with time.” Watanabe has already entrusted Nobuhiro Kikuchi as an apprentice with the hope that his passion and dedication for the craft process will be passed down through a number of generations.