Unique Swords with the Finest Edge

In a previous set of articles, brave acts with the Japanese spear were covered, as well as a few famous ones that still exist today¹. These examples illustrate the importance this weapon had in Japanese history. The same can be said about the Japanese sword, with a great amount of stories especially coming forth during the Edo period; these are often painted as an essential tool part of the arsenal of warriors during the Sengoku period, as well as being the symbol of the samurai class during the Edo period. Many of the tales concerning swords even touch on levels one would deem supernatural.

For this article, we’ll look at 3 unique stories that tell about amazing feats done with the Japanese sword. Each story has an interesting point to illustrate, which ranges from the greatness of the wielder to the sword itself being nothing short of mystical. As amazing the feat is, keep in mind that they shouldn’t be taken literally.


There is a legendary story that comes from the Ama-no-Iwatate Shrine (天石立神社, Ama-no-Iwatate Jinja) in Nara prefecture, which is home to a very large stone on its property. Measuring at about 26 feet long, 22 feet wide, and 6 feet & 1/2 high, this stone is fabled as the very one used by the Sun Goddess Amaterasu to seal herself in a cave. Today, it is a critical center piece behind the founding of Ama-no-Iwatate Shrine. However, the story we will be reviewing isn’t about the shrine’s origin, but concerns one of the more renown swordsmen during Edo period, whose name is Yagyū Muneyoshi (柳生宗厳).

A section for the Shinkage ryū scroll known as “mokuroku”. Here, instructions on kenjutsu is given with the use of an illustration consisting of a tengu. From Wikipedia.

A seasoned warrior on the battlefield during Japan’s warring years, Muneyoshi is the founder of Shinkage ryū (柳生新陰流) during the Edo period, a popular martial system that specialized in combat with the Japanese sword, which many still practice today. Well, it just so happens that the large stone of Ama-no-Iwatate Shrine also plays a significant role in how Muneyoshi founded his style.

There was a time Muneyoshi went on a training journey to further improve his sword skills. For this, he went to Ama-no-Iwatate Shrine and stayed there for awhile. One day, when he was training on the grounds of the shrine, a tengu (天狗, a long-nosed goblin with wings) suddenly appeared, as if challenging the warrior. Muneyoshi fought fiercely with the tengu, as they both went back and forth with blows. Channeling his intention, Muneyoshi swiftly delivered a downward finishing cut that the Tengu couldn’t stop, cleaving him in half. In the next moment, Muneyoshi’s opponent disappeared, and was replaced by the large stone that was originally sitting not too far from him while he was training. He was so intent on victory, that his blade was able to cut through stone.

Pic of Ittōseki. From Photo-AC.com

The large stone would later be called “Ittōseki” (一刀石, stone divided by a single sword swing) once an account of Muneyoshi’s feat was learned. It’s perfectly split from top to bottom at an angle, which would take an enormous amount of brute strength to achieve. The point to take from this tale is that near impossible feats can be achieved through sheer intention, where one is harmoniously in tune entirely on 3 levels: physical, mental, and spiritual.


This next story concerns the Mijima Shrine in Izu, located in Ooshima (eastern part of present-day Tokyo). Ittō Ittōsai (伊東一刀斎), the pioneer of the martial system known as “Ittō ryū” (一刀流), was residing there in his youth during a time when he wanted to learn kenjutsu. After a period of self-training through determination, the shrine’s head priest was moved, and decided to pass on a sword named Ichimonji (一文字) to the youth. This would be the 1st sword that Ittōsai would receive so he could begin to learn kenjutsu properly. Ichimonji was not only fabled to have a fine edge, it helped its young owner develop a skill that is quite a feat.

An example of a sword kept in a simple shirasaya, which is meant for storage especially during the cold season.

Before he became a renown swordsman, Ittōsai was described as a youth who had much potential in kenjutsu. The head priest acknowledged this as he convinced the youth to head on a journey to find a competent swordsmaster, which he agreed to fund. On the day he received Ichimonji, the sword was blessed with ceremonial rice wine, and passed on to him without proper fittings². Late in the night, right before his trip, Ittōsai heard commotions in the shrine, and learned that it was being looted by a gang of thieves. Unsheathing the sword which only had a wooden handle, he charged at the thieves. Despite them being armed and outnumbering him, the thieves fell to his sword one-by-one, as he displayed great handling. The last thief retreated to a room where wooded barrels used to store blessed rice wine are kept, and hid in an empty one hoping to escape later unseen. Ittōsai gave chase and, upon entering the room, was able to perceive where the thief was hiding. In one swift motion, he rushed at the barrel and cleaved through the barrel, which not only collapsed in two, the thief inside also fell along with it, severed from his torso down.

An example of a sake daru (酒樽), a barrel used for storing rice wine at a shrine. From Photo-AC.com.

This remarkable feat of cleaving both the wine barrel and the thief would years later serve as a secret technique taught to his highest student, which would be called “dō-giri” (胴斬り)³.


This tale involves Hōjō Tokimasa, a figure hailing from the illustrious Hōjō clan. Originally a military commander serving in the army of Minamoto no Yoritomo, Tokimasa became the 1st authority figure of the established military-ruled Bakumatsu during the early Kamakura period.

An ukiyoe of Hōjō Tokimasa. From Wikipedia.

After the establishment of Kamakura Bakufu, Tokimasa went through a period of being plagued by tormenting nightmares, which all involved the appearance of a demon. One night, he went to sleep in his chambers as normal, with his sword next to him. He proceeded to go through another round of nightmares, which made him agitated. As he turned on his bed, his right arm bumped into his sword, which then fell ontop of him. Suddenly, as if willed by a power not of his own, Tokimasa subconsciously drew this sword and swung it, instinctively cutting at the demon within his dreams. His sword instead cut off one of the legs from a table which a hibachi (火鉢, small heating pot) sits on. The exasperated Tokimasa woke up surprised at the scene around him. As he examined the damage done to the table, he noticed that the part of the table leg that was accidentally cut off had the carving of a demon on it. Suspecting that this was the cause of his nightmares, Tokimasa had this part discarded, and from then on, was able to have peaceful nights of pleasant sleep.

An image of the face of an oni, or demon. From AC-illust.com.

This sword of Tokimasa was actually named “Onimaru-kunitsuna” (鬼丸国綱). Known as one of 5 legendary swords in Japanese history, it is distinguished as being a “reitō” (霊刀), or “spirit sword”. This means the unique trait the the Onimaru-kunitsuna bear was the ability to cut things on a spiritual level. Since the small table was cursed by the carving of a demon, this sword was able to “will” its owner to severe the menace at its roots.


This concludes our coverage on stories concerning feats with Japanese swords. These tales were definitely penned to stir the imagination, illustrating famous figures and renown swords in a light of glory. While taking these types of stories as fact is abit difficult, one thing for certain is they are entertaining.

1) These articles can be read here and here.

2) A sword prepared for use would have what is called koshirae (拵), which includes a proper sword handle covered with shark skin and cotton wrap, a sword guard, and adorned with metal pieces. Since the Ichimonji was place at the shrine for safe keeping, it was prepped in shirasaya (白鞘), which consisted of a simple wooden sword handle, and housed in a non-lacquered sheath.

3) There is an article that talks on the general use of this term, which can be read here.

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.

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