Ninja Swords - Did They Exist Historically?

Often depicted as a straight bladed weapon with a square guard, the ninja sword (or "ninja-to") is an area of historical controversy. Contrary to the many fine examples of curve-bladed swords used by Samurai, the fabled "ninja-to" does not have living historical examples among today's antique swords in museums or private collections.

Historically, straight single-edged blades existed, and these were known as choku-to ("straight swords"). As the Japanese sword originally evolved from the Chinese straight-bladed jian, the Japanese sword was straight prior to the use of clay, which insulated the body and exposed the edge in the final heat treatment and water quenching - the result of which was a naturally formed curve due to metallurgical differences in the harder edge and softer body.

Thus choku-to existed primarily around the Koto period (pre-1596), roughly from 200 A.D. to 700 A.D. (or thereabouts). Some inaccurately refer to these as "ninja" swords, not understanding that this era completely predates historical ninja.

This brings us to the question: who were the historical ninja? The original ninja were not necesarily the fabled black-clad assassins as popularized in both Hollywood and even the Japanese movie industry. They were rather Samurai who trained in unconventional warfare, i.e. certain armored-forms of fighting, low-light combat, fighting in water or difficult terrain, etc. The closest parallel would be today's Navy SEALs or our Special Forces units who are intrinsically a part of our military. Early Japanese illustrations depict a ninja general in complete Samurai armor - indicating the general's samurai origins.

It was not uncommon for historical Samurai to not see eye-to-eye with the warlord (or "daimyo") they served and thus break from the ranks of other Samurai in pursuit of goals more "honorable" than blind servitude of their masters. Their actions, by default, classify these rogue-samurai as "dishonorable" and hence the stigma of ninja as "dishonorable" even though the rogue-samurai may have opted to follow the dictates of the heart rather than those of a dictator. It is not impossible for rogue-samurai to train peasants or others after them in samurai fighting arts and, especially, the unconventional warfare systems classified as "ninjutsu".

An examination of the swordsmanship styles of some of today's historically-accurate ninjutsu schools reveals that much of the swordsmanship techniques are in fact based on period Samurai kenjutsu. Techniques include katana vs. katana, wakizashi vs. katana, tanto vs. katana, or unarmed vs. katana. There are also techniques of armored fighting and many variants thereof, including the use of naginata (polearm), yari, etc. Clearly these break the stereotype of the "Hollywoodized" ninja which can no longer be taken as a historically accurate depiction of the true ninja-samurai.

As a product of the swordsmanship techniques, it can be derived that the curved blade - and not the straight blade - was the preferred weapon. Historically there were a form of katana which were worn with a shorter blade in proportion with its hilt. Some "merchant samurai" were known to carry these; they were not full samurai by lineage but acquired the title financially from the daimyo. These "merchant" katana were not full length katana due to the stipulations of blade-length. Thus, they were often worn in the same furnishings as full-length katana - no-one could tell the difference from the outside.

However, the essence of ninjutsu is deception. A shorter blade is far more quickly drawn than a longer blade, and much of classical swordsmanship predicated distancing based on standard blade lengths. Thus a ninja-samurai or ninja would have the element of surprise in drawing his sword much quicker and at a closer distance than his opponent with a regular-length blade. This split-second advantage may be the turning point in a conflict.

Today's historically-accurate ninjutsu arts seem to promote both katana-length and wakizashi-length blades which, by default, were the primary sword of the Samurai; being shorter, they were more apt for indoor fighting and thus were the sword the Samurai had beside him when eating, sleeping, or bathing. While little distinction is made today, true wakizashi were single-handed weapons while uchigatana were dual-handle length weapons, though the blade lengths were the same.

Thus, historically, what was a ninja-sword? It would seem whatever weapon was acquired or required at the time of fighting was the ninja's weapon - be it a polearm, a staff, a katana, a wakizashi, a tanto, or his own person.

Additional Reading

• Article: "The Wakizashi: That Other Japanese Sword" - Sword Forum Magazine Online, Summer 1999 Edition (accessible via Main Menu.)