Shinai (竹刀)

Shinai is a substitute sword made of bamboo used in the Japanese martial art of kendo for training or for hitting or pushing against armor (Kendo) in tournaments. In the Azuchi-Momoyama period (1558-1600), some kenjutsu, or sword fighting, schools began using bamboo swords covered with leather sleeves and called 'fukuro shinai' for sparring practice, and the Edo period (1603-1868), with the development of armor, saw the appearance of the 'warijinai' (split bamboo sword).
They are occasionally called 'chikuto.'

There is a theory that the name 'shinai' comes from the Japanese word 'shinau' (bend).
Due to this, although usually written with the characters for 'bamboo' and 'sword,' it is sometimes written with the character for 'bend.'
The forerunner of the All Japan Kendo Federation (AJKF) was the All Japan Shinai Competition Federation.

With shinai replacing 'bokuto' wooden swords, it became possible for people to directly hit each other in tournaments. The following describes warijinai unless otherwise mentioned.

Summary

Shinai are made by cutting a piece of bamboo (usually Taiwanese 'keichiku' bamboo or Japanese 'madake' bamboo) lengthways into eight, four of which are then tied together using deer skin at the tip and the grip.
A piece of string called a tsuru is tied along one side from the tip to the tsuka (hilt), and the side with the tsuru is called 'mine' and the other side is called 'habu.'
Nowadays, durable carbon fiber shinai are also used.

The tsuba, or guard, is usually made of leather or plastic (though some are made of wild boar or shark skin), and is disk-shaped with a hole in the center. The tsuba is slid from the tsuka-gashira (pommel) to the tsuka and is held in place with a tsubadome, made of non-slip rubber, which is also put on from the tsuka. In recent years, combined tsuba and tsubadome have started to be sold. Since the tsuba can be easily removed, it is possible to carry it separately from the shinai in the shinai bag. However, since it can be easily removed, it can also come off easily while training.

Because of the noise they make, shinai are also used as weapons in overseas pro wrestling, such as the WWE, where they are known as kendo sticks.

Length

Although originally the same length as Japanese swords, towards the end of the Edo period, many people started using shinai over 1.2 meters long since it gave them an advantage in tournaments (the famous Susumu OISHI used a very long shinai of 5 shaku 3 zun, or about 161 cm), and due to the above situation it is said that people began to use shinai longer than swords.

To regulate the increasing lengths of shinai, the Kobusho (a military academy set up by the Edo Shogunate) declared in 1856 that, 'shinai longer than 3 jaku 8 sun (about 95cm) are not acceptable' and this became the set length. The tradition of using shinai of 3 jaku 8 sun was maintained after the Edo period. However some swordsmen used short shinai, as if they were using a short sword. Tesshu YAMAOKA and Hiromichi NAKAYAMA are well known for using this kind of short sword.

Currently there are different length of shinai available; common sizes are size 36 (3 jaku 6 sun, 109 cm) for primary students, size 37 (3 jaku 7sun, 112cm) for junior high school students, size 38 (3 jaku 8 sun, 115cm) for high school students, university students and adults, and size 39 (3 jaku 9 sun, 118cm) for university students and adults. With an increase in the average of height of Japanese, the longest shinai, for university students and adults, was also increased from 3 jaku 8 sun to 3 jaku 9 sun.

Shape

The tsuka is usually circular, but there is also an oval-shaped tsuka, known as kobangata. Some people say a kobangata tsuka is easier for beginners to use since the feeling of holding the oval-shaped tsuka is similar that of holding a sword.