Essay on historical Ninja-to, a ninja sword


Ninja-to, a short sword in scabbard of usual measurements

Probably hardly any weapon used by Japanese Ninjas 忍者 evokes so much arguing and discussions like Ninja-to 忍者刀, or Shinobikatana 忍び刀, a ninja sword. The main issues of the “disputes” are whether this sword was straight or curved and what was the main way of using it. There have been many articles and essays written about this kind of Japanese sword. However, many of these materials are unfortunately based on what could the authors meet with on the screens rather than on a serious study of Japanese sword (Nihonto 日本刀 in Japanese), or a study of the martial art (Ninjutsu 忍術) itself.

It is shocking how the image of ninja sword given by the film industry got deep in the consciousness of people around the world, even in Japan itself. Yes, even in modern Japanese books, the authors of which generally do not care much about studying the history, we found drawings of ninja-to with straight blade, square tsuba 鍔 and saya 鞘 with removable end. Then no wonder that we can meet exhibits with a tag saying it is a real ninja sword when visiting modern museums with Ninjutsu exhibitions. And why not?, these sword are in most of the movies anyway, so there must be something true about it. Let’s have a closer look on how is it with ninja sword in reality without trying to find anything fantastic.


This is some older photography of Masaaki Hatsumi, Soke (grandmaster) Togakure Ryu Ninjutsu in one of the positions with Ninja-to

Let´s just very simply describe the evolution of Japanese sword in relation to its shape. From the point of view of studying the history of Nihonto we can find several types of swords with straight blade. One of them is Ken 剣, with double-sided edge. This sword however, is connected religion and mythology rather than ninjas. Another swords were Chokuto 直刀, with the cutting edge only on one side, ending with a skew cut of the tip and these appear with hardened part – Hamon 刃文. These swords were usually mounted in Tachi 太刀 style of koshirae (mounting) and worn hanging on two stripes under the belt on the left side with the edge facing ground. Chokuto used to be a part of the gear of Japanese nobility and therefore it has nothing to do with ninjas.

The swords with straight blade are typical for the period around before the 9th century. Swords with big curvature of the blade followed. The reason for using curved blades and the curvature to origin at the first place was that the curvature gives the swords longer durability and better ability to cut in comparison to the used strength. Swords with big curvature lasted approx. up until the 16th century, when they got replaced with sword with smaller curvature of the blade. The blades got straighten out the most in Kanbun period 寛文 (1661 – 1673). Swords of that time were only of minimum curvature, often only a few millimeters. This trend soon went aside and the blades were again produced with bigger curvature, around 15 mm and more. Nevertheless in every of these mentioned periods originated swords that deviated from the common standards, swords of no “category”. Where to place the blade of Ninja-to then?

With a deeper study we find out that the blades of Ninja-to differ in many ways from the swords of common shape of that time. It was much shorter than blade of classic Katana 刀 and its design and production was by far not that precise. With swords, ninja let to make for themselves, the focus was mainly on their practical use in fight, disregarding the aesthetic side of the weapon as an artistic and spiritual object. In this matter we also need to mention the fact that ninja had just a very few chances to have their swords made by master swordsmiths of the top class. It was not unusual that the swords were made by master swordsmiths who were actually part of the ninja community, family or clan. The blade had mostly a plain edge, but there are also blades with rough edges in shape of saw. Such blade did not cut but actually tore out the flash from opponent’s body.


Masaaki Hatsumi demonstrates the techniques of Bikenjutsu with his student Ken’ichi Someya. Notice the shape of the Ninja-to blade used by Hatsumi Sensei

Here we get to the essence of Ninja-to – it is actually a weapon that closely relates to ninja tradition, their families, clans or individual schools, Ryu-ha 流派. Their shape reflects especially the needs of their wearers. The edge was often used for cutting through door and window frames. Short blade allowed easier manipulation on short distance in tight spaces and also allowed faster drawing. Because Ninja-to was not usually that long neither it was elegant like samurai sword, his usage was different from the traditional Japanese Kenjutsu 剣術. Samurai 侍 could effectively cut with the edge of his sword and therefore he could use precise and elegant body movements. On the contrary, ninja had to use his whole body to make his cuts effective. The hips were during the technique often twisted much more in order to equal the length of the weapon and therefore more effective techniques could be used. Less fine edge of ninja sword made ninja to rely more on thrust attacks and cutting strokes rather than cuts common for samurai swords. The skills in sword techniques were mentioned in Bikenjutsu part.

Let’s just get back to the sword itself now and let’s split it into single parts and have a closer look. Although the blade was shorter, the scabbard – Saya 鞘 was as long as usual samurai Katana scabbard in order to hide the true length of the blade. This was the surprising fact when drawing Ninja-to. The free space on the bottom of Saya was used to carry messages, as a place for blinding powders or explosives. These or similar sword boxes also appeared with traditional samurai swords. In their cases these were used for carrying a little knife Kozuka 小柄 and skewer Kogai 笄. Hidden boxes could be also used to carry coins or other things that would fit. Nevertheless the system of hidden boxes in the scabbard of Japanese sword and especially in its lower part was in case of Ninja-to used much more.


Blinding powder hidden in free space in the sword’s scabbard

Tsuba 鍔, a hand guard or hand protection, often a delicate and valuable work on samurai swords, in case of Ninja-to often made in more humble conditions. It often had a shape of a square without any working what so ever, but not in every case. Square shaped tsuba, in Japanese terminology called Kukagata 角形, quite regularly appeared on samurai swords as well. Handguard on Shinobigatana was in comparison with samurai sword Tsuba often more robust and wider with respect to its various usages. Such Tsuba could have been used for example as a support when climbing over a wall.

Tsuka 柄, or a sword handle, had a classic shape and was a bit longer than Tsuka of samurai Katana in order to help the manipulation with the sword. Unfortunately today we often meet with replicas of ninja swords with Tsuka much longer than it really was in the history.

Let’s just stop a bit with Sageo 下緒, or a string fasten to an eyelet called Kurigata 栗形 on the side of Saya. Sageo was a regular accessory of Koshirae 拵 type of sword set and was used for example to fasten the sword to the belt or to tie the sleeves of Kimono 着物 before actual fight, etc. In case of Ninja-to Sageo was a lot longer and more robust so that it could have been used for example for tying up the captured enemies. Straining the Sageo above the ground could have been used in order to slow down the pursuers. Sageo have been also used for creating an improvised seat for observance on the trees. We can find many ways of using Sageo in terms of Ninpo 忍法 in historical materials.


Shihan Ken’ichi Someya in the guard with Ninja-to originating from Togakure Ryu 戸隠流

What to say for the conclusion… Probably just that ninja looked on his sword as one of many weapons within his equipment and although he respected its value, he never pay his sword such respect as it was in common with samurais, whose swords were kept as family treasures. Despite of that, or just because of that Ninja-to was an important weapon in the history of martial art called Ninjutsu, although in comparison with beautiful Tachi and Katana (often swordsmiths´ masterpieces) Ninja-to seems to be just a little bit more than „machete“. Regarding the shape of the blade, it is possible to meet straight blades used by ninja, but it was unlikely with the swords. These blades more likely appeared as Shikomi-zue 仕込み杖. Shikomi-zue was a weapon similar to stick that concealed blades of various lengths and shapes, chains or other weaponry equipment that could have been used in the history of ninja. But that is a different story. Anyway, looking at the shape of Ninja-to we could say that it could not had been different at mere glimpse from an ordinary sword at certain period. If it was, ninja would be immediately discovered and that was definitely not acceptable for these warriors.


Concealed sword in a stick – Shikomi-zue 仕込み杖 with blade signed Gassan 月山, blade – the beginning of the 16th century; fittings – Bakumatsu period 幕末 – Meiji 明治, 2nd half of the 19th century. (from collection of Jakub Zeman)

Prepared by:

Pavel Slavik

Bujinkan Dojo Prague



tel.: +420 736 208 050

Used materials:

book “Ninjutsu, history and tradition“ from Masaaki Hatsumiho

book “Sengoku Ninpo Zukan“ from Masaaki Hatsumiho

magazine “The Hiden Budo and Bujutsu“

article  “Ninja sword – fact or myth?“ from Pavel Bolf