A Glossary of Ninjutsu Terms

Ashiko

足鉤

Spiked bands strapped to the feet, used with shukō for climbing walls and trees. The foot equivalent of hand claws.

Like most of the specialised ninja tools, ashiko are documented in later manuals rather than contemporary accounts, and their practical use is debated. They appear in modern demonstration and training but are legally restricted in several jurisdictions.

Bansenshūkai

万川集海

A Japanese manual compiled in 1676 by Fujibayashi Yasutake, collecting the methods of the Iga and Kōga traditions. It is the largest surviving source on ninjutsu.

Written roughly a century after the period it describes, during peacetime, it is a retrospective compilation rather than a field document. Along with the Shōninki (1681) and the Ninpiden, it forms most of what is actually known in writing.

Bujinkan

武神館

A martial arts organisation founded by Masaaki Hatsumi, teaching a curriculum drawn from nine traditional schools, three of which are described as ninjutsu lineages.

The Bujinkan is the largest single route through which ninjutsu reached the West from the 1980s onward. The historical continuity of its lineages is disputed by some researchers; the training itself is a documented modern practice.

Dōjō

道場

The hall or space where a martial art is trained. Literally “place of the way.”

In ninjutsu practice the term is used loosely, since a substantial part of the curriculum — body movement, stealth, terrain work — cannot be trained indoors at all.

Iga and Kōga

伊賀・甲賀

Two neighbouring regions of central Japan, in modern Mie and Shiga prefectures, historically associated with the families who practised shinobi methods.

Both were mountainous, difficult to govern and unusually independent of central authority, which is the likelier explanation for their reputation than any secret tradition. Iga was overrun by Oda Nobunaga in 1581.

Kachi-iro

勝色

A very dark indigo, almost black in low light. The name puns on katsu, to win, which made it a favoured colour among samurai.

It is the colour most often given for historical shinobi clothing, and it matters practically: true black reads as a solid silhouette at night, while dark indigo breaks up against shadow. Repeated indigo dyeing also stiffens and strengthens cotton.

Kata

型

A fixed sequence of movements practised as a training form.

Kata are central to many Japanese martial arts and comparatively marginal in ninjutsu, which tends to train principles applied to changing conditions rather than set sequences.

Keikogi

稽古着

The standard Japanese training garment — jacket, trousers and belt. Commonly shortened to gi.

A judo or karate keikogi and a shinobi shozoku are built on the same basic pattern. The differences are the hood and mask, the tapered and tied legs, and typically a heavier cloth.

Kuji-kiri

九字切り

A sequence of nine hand seals, each paired with a syllable, used as a focusing and centring practice.

Its origin is not ninjutsu. The nine syllables come from a fourth-century Chinese Daoist text and entered Japan through esoteric Buddhism, where they remain in use. Their association with ninja is a later borrowing, heavily amplified by film, where the seals are usually shown as magic. In practice they function as a concentration ritual.

Kunoichi

くノ一

A female practitioner. The word is written using three characters that together form the character for “woman.”

The term is attested in the historical manuals, though the popular image of the kunoichi as a seduction specialist is largely a twentieth-century fiction.

Kyahan

脚絆

Cloth wraps bound around the lower leg from ankle to knee, worn to support the calf and keep loose trouser fabric out of the way.

Kyahan were ordinary Japanese travelling wear, not a ninja invention — farmers, couriers and soldiers all used them. They remain part of a full shinobi shozoku, usually sold as leg wraps.

Ninja

忍者

The Sino-Japanese reading of the same characters read natively as shinobi-no-mono. Both mean a person who practises concealment.

“Ninja” is the reading that reached English and now dominates worldwide, but it was not the common term in the historical period; contemporary Japanese sources generally use shinobi.

Ninjatō

忍者刀

The straight-bladed, square-guarded sword shown in films as the standard ninja weapon.

There is no evidence it existed historically. No surviving example predates the twentieth century, and the historical manuals describe ordinary swords. The ninjatō appears to be a film and stage design that became real by being manufactured. Worth knowing, because it is the single most common thing people believe about ninja equipment that the record does not support.

Ninjutsu

忍術

The Japanese discipline of concealment, infiltration, reconnaissance and irregular warfare, and the modern martial art derived from it.

Often spelled ninjitsu in English-language schools, including this one. Both are romanisations of the same word; ninjutsu is the more standard transliteration. Historically the term covered a far wider set of skills than fighting — geography, meteorology, disguise, chemistry and intelligence gathering all sat inside it.

Ninpō

忍法

A term used alongside ninjutsu, generally to indicate the philosophical or ethical dimension rather than technique alone.

The distinction is one modern schools draw more sharply than the historical sources do.

Obi

帯

The belt that closes the jacket of a Japanese training garment.

In most modern martial arts the obi also carries rank by colour. In some ninjutsu schools it does; in others it does not, and rank is recorded separately.

Sensei

先生

Teacher. Literally “one who has gone before.”

Shinobi

忍び

The native Japanese reading for a practitioner of concealment; the term used in most historical sources.

The verb shinobu carries a double sense: to conceal, and to endure. Both readings are meant.

Shinobi shozoku

忍び装束

The training uniform of ninjutsu practice: a wrap jacket, tied trousers, hood and mask, hand coverings and a belt, made in heavyweight cotton.

The historical position is worth stating plainly. Operating shinobi are believed to have dressed as whoever they needed to appear to be — farmers, monks, merchants — because a distinctive uniform defeats the purpose of concealment. The all-black outfit owes much of its familiarity to kabuki theatre, where stagehands wore black to read as invisible to the audience, a convention later applied to ninja characters.

What the shozoku unambiguously is, is the working garment of modern ninjutsu training: cut for rolls, falls, ground work and climbing, and made heavy because that training destroys light cloth. Training weight runs 12 to 14 ounces; costume reproductions are typically 6 ounces and fail at the seams inside a season. Kage Ninja Gear has made a 14oz cotton version since 2009.

Shukō

手鉤

Spiked bands worn across the palm, used for climbing and, in some accounts, for catching a blade.

Also called tekagi. Paired with ashiko for the feet. Legally restricted in a number of jurisdictions.

Shuriken

手裏剣

Small thrown blades. The familiar star shape is hira-shuriken; the straight spike form, bō-shuriken, is older and more widely documented.

Shuriken were used across Japanese martial traditions rather than exclusively by shinobi, and served mainly to distract or delay rather than to kill. Possession is restricted or prohibited in many countries and several US states.

Tabi

足袋

Japanese socks with a split between the big toe and the rest, allowing them to be worn with thonged footwear.

Jika-tabi are the outdoor version with a rubber sole, still worn by Japanese construction and agricultural workers. The split toe gives a genuine grip advantage on uneven ground and is the reason tabi remain standard for outdoor ninjutsu training rather than a period affectation.

Taijutsu

体術

Unarmed technique. Literally “body art” — striking, throwing, grappling, rolls, falls and movement.

Taijutsu is the foundation layer of most ninjutsu curricula, on the reasoning that weapons handling rests on body mechanics that have to work without them first.

Togakure-ryū

戸隠流

A school of ninjutsu, traditionally dated to the twelfth century, which forms one of the three ninjutsu lineages taught within the Bujinkan.

Its documented history before the twentieth century rests largely on transmitted scrolls rather than independent record, and is contested among researchers.

Zukin

頭巾

The hood and face covering of the shinobi shozoku, usually a single long strip of cloth wrapped around the head and across the face.

Zukin were ordinary Japanese headwear worn for warmth, dust and sun long before any association with ninja. In modern uniforms the hood and mask are often made as one piece.