The use of bamboo swords or shinai along with armor or bogu in Japanese sword arts is a relatively recent phenomenon. It is believed that the father and son duo of Yamada Heizaemon Mitsunori and Naganuma Shirozaemon Kunisato developed and improved the bokuto and shinai, as well as the bogu.
There was good reason for the invention of the bamboo sword.
Before the shinai, samurai would practice with the wooden sword – bokken or bokuto. It is not surprising that they would often hurt their training partner. Even with a wooden sword (and not a sharp katana), there were deaths. In fact, Miyamoto Musashi is said to have killed an equally prominent swordsman Sasaki Kojiro with a legendary bokken carved from an oar.
Then the bamboo shinai was invented. The modern shinai has evolved from the hikihada or bamboo training stick wrapped in leather. This type of sword, also called the fukuro-shinai because the leather is shaped like a bag, is still used in many traditional kenjitsu schools including Yagyu Shinkage Ryu.
The modern shinai uses four slats of bamboo. The very origin of the word shinai is a reflection of the flexibility and the bendability of bamboo that allows for the amazing use of bamboo swords in kendo.
The Characteristics of the Shinai
The word ‘shinai’ comes from a Japanese verb that means “to flex, to bend”. Another phrase that is linked to it shinai take means “flexible bamboo”.
The shinai represents the soul of the wielder, just as the samurai’s sword represented his soul. It has a hand grip, front, back and hand-guards. The entire length of the shinai can be used for blocking or paring, but only the last third part can be used for a strike.
The Amazing Use of the Shinai
All the hitting and cutting techniques in kendo are based on one downward cut that has proved to be most effective in battle. In this simple form, the shinai is held with both hands, followed by movement, a strike and the kiai or warcry. In the most amazing examples from tournaments in Japan, these three steps are carried out in a flash, with flying shinai and fluid, sweeping motion. The movement usually starts in the lower abdomen, and is carried to the upper body towards the wrists and elbows that will do the striking. This movement will also drive the kendoka to his target in the same fluid movement. Here lies part of the beauty of the form of kendo.
A combination of full and long cuts or short cuts make up the strikes. Long or full cuts are made by shinai lifted above the head. In shortened cuts, shinai travel the shortest distance, and cut down reaction time.
Sometimes, there are long, tense periods of seme between masters, followed by quick clashing of the shinai.
And while kendo is a “modern Japanese martial art” with a focus on self-improvement, there is no reason why the shinai, for a kenshi with the right spirit and mastery cannot disarm an opponent or bring him to his knees.