Fun with Fukuro Shinai

Recently I became interested in adding fukuro shinai1 to my training. Gathering some materials together, I managed to make my own working versions. This is a great substitute for a bokken in one’s kenjutsu training, permitting you to actively strike at your training partner trying to outbest him/her with technique without the need to stop inches away to avoid seriously damaging one another. This is pretty much the roots to the conception of this safe training tool, which I will explain in detail below.

Two fukuro shinai I recently made, as an experiment. A little bigger (fatter?) than intended, but works as intended.

The fukuro shinai was developed by a strategist and warrior named Kamiizumi Ise-no-Kami Nobustuna (1508? – 1577). Born in Joshu2 during Japan’s tumultuous era of constant warring called Sengoku Jidai, Nobutsuna studied bujutsu from various martial schools such as Kage ryu, Nen ryu, and Shinto ryu. He would also take part in battles and other means to hone his skills before starting his own system, Shinkage ryu Heiho.

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A demonstration of kata using fukuro shinai (hikihada shinai) at Itsukushima Jinja in Japan. Taken by Nyuyen Thahn Thien on 11/2005. From Wikipedia.

There is a theory of how Nobutsuna came up with the idea of the fukuro shinai within the school of Shinkage ryu. It is said that Nobutsuna would go on “shokoku rurou no tabi”3, or training expeditions, with a few of his top students. They would carry with them specific weapons, primarily a sword. Since these are real swords, they are subjected to all sorts of harsh conditions, such as dirt, rain, moisture, and collisions with nature. To protect their swords, they would put them in a soft, padded case called a saya fukuro4. While training, normally blunted swords or bokuto would be used, but practioners would have to hold back so not to hurt (or kill) each other. To remedy this, Nobutsuna decided to get bamboo from a bamboo forest, insert it in the saya fukuro, and use it in place of a real sword. Thus the birth of the fukuro shinai. Now, warriors can go all out and strike each other with these fukuro shinai and utilize the kenjutsu techniques they’ve studied for years, and not worry about serious injuries.

Historically, the fukuro shinai was called “Hikihada shinai”5 under Shinkage ryu, where the shinai is covered with a bag-like leather sleeve from the tip down to where the handle starts. Many other koryu schools adopted this type of fukuro shinai. There are other types of fukuro shinai out there. For example, Jiki Shinkage ryu’s fukuro shinai is covered from tip to about halfway point of the shinai. Others may use a tsuba (sword guard), although Shinkage ryu does not utilize this.

A screen capture of practitioners of Kashima Shinden Jiki Shinkage ryu using a variation of fukuro shinai during the 33rd All Japan Kobudo Demonstration.

Here’s a short rundown on the process for making the fukuro shinai that is used in Shinkage ryu, according to a related blog6:

① Bamboo is collected as it is grown outdoors during the winter time. It is cut from its joint at the desired length.

② For a year, it is dried in a shaded area until all water and moisture is gone.

③ Once it dried and cleaned, it is then split several times, from 6 to 8 times7. The splits happen from the tip of the bamboo down to the midway point. This allows the fukuro shinai to bend with impact.

④ The slivers of the bamboo are then taped at 3 points. These points are not taped tightly; the tape is applied just enough where the slivers have space inbetween each other, and can compact upon collision.

⑤ The handle part is then made fine with sand paper.

⑥ The fukuro, or cover for the bamboo is cow hide that is painted with a red lacquer. It also comes with a kawa himo8, which acts like handle wrap if needed.

⑦ The fukuro is then sewn to fit like a sleeve. The stitching acts as an indicator for the blade.

Speaking of safety, the fukuro shinai actually predates the shinai, a similar safe training tool utilized in kendo. While they both share similarities (most obviously both being made out of bamboo), the differences stand out more. For example, fukuro shinai is wrapped with a slip on cover, where as the shinai doesn’t, but instead is padded heavily at the tip. Construction of the shinai differs abit as well (i.e. split 4 times, much more sturdier, a wire attached from tip to tsuba to indicate back of blade, etc.), while a tsuba and a wrapped tsuka is considered the standard. Possibly the main difference between the two lies in how they are used; while the fukuro shinai is swung in a slashing motion, the shinai is primarily used in a stabbing motion.

The shinai, used in kendo. From Wikipedia.

In kendo, bougu9, or protective gear, is used to keep practitioners safe. The reason being that since kendo is sport-oriented and practitioners score points striking specific areas such as the hands, face, and chest, protective gear is a must to avoid internal injuries as practitioners competitively strike and (more fatally) thrust at these areas with force. For koryu bujutsu, on the other hand, protective equipment is usually not necessary, possibly because training one’s sword cuts is still systematic and controlled.

In ending, the fukuro shinai is an essential training tool for those who study classical Japanese martial arts, for it is supple and designed to not do harm (at least, not too much) upon impact. It is something I will be using more when engaging in randori-like sessions with training partners.


1) 袋竹刀. Commonly read as “Encased Bamboo Sword”, this was not always the case. While “fukuro” (袋)remains the same, at one point “shinai” was represented by the Chinese character “撓”. This character, used as a verb pronounced as “shinau”, means to bend and be flexible, with a nuance towards the bamboo. So fukuro shinai can be written as (and is at times so in Japan) “袋撓”.

Possibly the original writing for fukuro shinai in Shinkage ryu was “韜”. A rather complex character that is rarely used in Japan, it possesses a multitude of rather deep & intricate meanings depending on how it is used , such as “strategy”, “hidden talent”, and a “weapons-carrying bag”. It seems that in the case of the fukuro shinai, the 3rd meaning may have been the intended use.

The Chinese characters “竹刀” are actually read as “chikuto”, with the proper meaning of “bamboo sword”. There are records of this word being used as so with said pronunciation. So why is it that “竹刀” represents the “shinai” phonetic? Not sure, but in Japan’s history it was not unusual to use the phonetics of one character and attach it to a completely different character for the sake of written comprehension. Sorta like having 2 meanings both verbally and written form.

On a similar note, “shinai” is the same pronunciation of another Japanese word written as 死ない, meaning “not to die”. Since the purpose of the fukuro shinai is to avoid death while training in kenjutsu, I wonder if this word also had an influence on how this training tool was named…?

2) Also called Kozuke no Kuni (Kozuke Province) in the past, now known as Gunma Prefecture.

3) 諸国流浪の旅. A journey where warriors would be away from home for months’ (or years) end in the wild for the sake of training their skills. Same as kaikoku shugyo.

4) 鞘袋

5) 蟇肌竹刀, or correctly written as 蟇肌撓 in Shinkage ryu.  The name means “Toad-skinned Bamboo Sword”. Although originally cow’s hide or deer skin was used for the the leather sleeve, once the red lacquer was applied it would resemble the skin of a hikigaeru (Japanese common toad).

6) From the blog “Shinkage ryu Heiho”, run by Mouri Keisuke. This can be accessed here.

7) Some schools are known to split the bamboo as few as 4 times, and as much as 8 times.

8) 革紐

9) 防具

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