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Ninja facts for kids

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In 1817, Hokusai drew a perfect example and the original pattern of ninja.
Eight Hundred Heroes of Our Country s Suikoden 12
Jiraiya, ninja and title character of the Japanese folktale

A ninja is a kind of spy or assassin who lived in Japan beginning in the 14th century. The functions of a ninja included siege and infiltration, ambush, reconnaissance, espionage, deception, and later bodyguarding and their fighting skills in martial arts, including ninjutsu. Their covert methods of waging irregular warfare were deemed dishonorable and beneath the honor of the samurai.


Ninja (or shinobi) were a mystery in the History of Japan. The correct Japanese word for these warriors was shinobi-no-mono, which literally means "people who survive/endure". Ninja is easier to say; this is why it is more widely used. Shinobi-no-mono is the native Japanese word for ninja, while ninja is the Sino-Japanese word. Ninja warriors created secret associations and took part in many political killings. Their mystery comes from two ideas: 1) they always participated in secret spy operations and political killings; 2) ninja were hired by heads of armies as paid warriors (mercenaries). The art of fighting which was used by ninja was called ninjutsu, which was a combination of shinobi-no-jutsu and shinobi-jutsu.

Many people thought ninja were not normal people. People thought they could fly and had supernatural skills. Ninja existed during the entire history of Japan, but ninja only became specially trained people at the beginning of the 15th century. They mainly trained in the regions of Iga and Koga.

Ninja were involved in samurai wars and were hired by samurai for different missions, but at the same time samurai did not accept them as noble warriors because most of the ninja came from lower social classes. They were dangerous and could not be controlled. Their methods of fighting did not fit the samurai code. The samurai code was a code of honor. For example, the samurai warrior would show his rank and would only fight a samurai of equal or higher rank. Japanese land lords (daimyo) widely used the services of the Iga and Koga ninja in the period of 1485-1581. But in 1581, one of the three daimyo who united Japan – Oda Nobunaga attacked ninja from Iga province. The ninja remained alive and ran to the provinces Kii and Mikawa, where Tokugawa Ieyasu protected them. Later, Oda Nobunaga was killed by a samurai named Akechi Mitsuhide, who later became an enemy to Tokugawa Ieyasu.

The art of ninja fighting was passed down from father to son, or from master (sensei) to their best students. But in the middle of 17th century, Nakagawa Sosuntzin created a ninja school in the Mutsu Province. It was called Nakagawa-ryu and taught the ninjutsu method of fighting. Nakagawa Sosuntzin himself trained a group of 10 men, which he called Hayamiti-no-mono (men of the short hit). Ninja were taught many more things than a samurai. They had to be skilled at handling swords, spears, bows and many other weapons; but also they had to know about explosive and poisonous substances, to be a good path finder and to survive in different situations. Usually they were trained from young age and had to keep a very specific physical shape. Ninja were not allowed to be too light or too heavy. A ninja who could read and write was very appreciated.


The ninja were stealth soldiers and mercenaries hired mostly by daimyōs. Their primary roles were those of espionage and sabotage, although assassinations were also attributed to ninja. Although they were considered the anti-samurai and were disdained by those belonging to the samurai class, they were necessary for warfare and were even employed by the samurai themselves to carry out operations that were forbidden by bushidō.


The skills required of the ninja have come to be known in modern times as ninjutsu (忍術), but it is unlikely they were previously named under a single discipline, rather distributed among a variety of espionage and survival skills. Some view ninjutsu as evidence that ninja were not simple mercenaries because texts contained not only information on combat training, but also information about daily needs, which even included mining techniques. The guidance provided for daily work also included elements that enable the ninja to understand the martial qualities of even the most menial task. These factors show how the ninjutsu established among the ninja class the fundamental principle of adaptation.

This diagram from the Bansenshūkai uses divination and esoteric cosmology (onmyōdō) to instruct on the ideal time for taking certain actions.

The first specialized training began in the mid-15th century, when certain samurai families started to focus on covert warfare, including espionage and assassination. Like the samurai, ninja were born into the profession, where traditions were kept in, and passed down through the family. According to Turnbull, the ninja was trained from childhood, as was also common in samurai families.

Outside the expected martial art disciplines, a youth studied survival and scouting techniques, as well as information regarding poisons and explosives. Physical training was also important, which involved long-distance runs, climbing, stealth methods of walking and swimming. A certain degree of knowledge regarding common professions was also required if one was expected to take their form in disguise. Some evidence of medical training can be derived from one account, where an Iga ninja provided first-aid to Ii Naomasa, who was injured by gunfire in the Battle of Sekigahara. Here the ninja reportedly gave Naomasa a "black medicine" meant to stop bleeding.

With the fall of the Iga and Kōga clans, daimyōs could no longer recruit professional ninja, and were forced to train their own shinobi. The shinobi was considered a real profession, as demonstrated in the 1649 bakufu law on military service, which declared that only daimyōs with an income of over 10,000 koku were allowed to retain shinobi. In the two centuries that followed, a number of ninjutsu manuals were written by descendants of Hattori Hanzō as well as members of the Fujibayashi clan, an offshoot of the Hattori. Major examples include the Ninpiden (1655), the Bansenshūkai (1675), and the Shōninki (1681).

Modern schools that claim to train ninjutsu arose from the 1970s, including that of Masaaki Hatsumi (Bujinkan), Stephen K. Hayes (To-Shin Do), and Jinichi Kawakami (Banke Shinobinoden). The lineage and authenticity of these schools are a matter of controversy.


The ninja did not always work alone. Teamwork techniques exist: For example, in order to scale a wall, a group of ninja may carry each other on their backs, or provide a human platform to assist an individual in reaching greater heights. The Mikawa Go Fudoki gives an account where a coordinated team of attackers used passwords to communicate. The account also gives a case of deception, where the attackers dressed in the same clothes as the defenders, causing much confusion. When a retreat was needed during the Siege of Osaka, ninja were commanded to fire upon friendly troops from behind, causing the troops to charge backwards to attack a perceived enemy. This tactic was used again later on as a method of crowd dispersal.

Most ninjutsu techniques recorded in scrolls and manuals revolve around ways to avoid detection, and methods of escape. These techniques were loosely grouped under corresponding natural elements. Some examples are:

  • Hitsuke: The practice of distracting guards by starting a fire away from the ninja's planned point of entry. Falls under "fire techniques" (katon-no-jutsu).
  • Tanuki-gakure: The practice of climbing a tree and camouflaging oneself within the foliage. Falls under "wood techniques" (mokuton-no-jutsu).
  • Ukigusa-gakure: The practice of throwing duckweed over water to conceal underwater movement. Falls under "water techniques" (suiton-no-jutsu).
  • Uzura-gakure: The practice of curling into a ball and remaining motionless to appear like a stone. Falls under "earth techniques" (doton-no-jutsu).


The use of disguises is common and well documented. Disguises came in the form of priests, entertainers, fortune tellers, merchants, rōnin, and monks. The Buke Myōmokushō states,

Shinobi-monomi were people used in secret ways, and their duties were to go into the mountains and disguise themselves as firewood gatherers to discover and acquire the news about an enemy's territory... they were particularly expert at travelling in disguise.

Komuso Buddhist monk beggar Kita-kamakura
A komusō monk is one of many possible disguises.

A mountain ascetic (yamabushi) attire facilitated travel, as they were common and could travel freely between political boundaries. The loose robes of Buddhist priests also allowed concealed weapons, such as the tantō. Minstrel or sarugaku outfits could have allowed the ninja to spy in enemy buildings without rousing suspicion. Disguises as a komusō, a mendicant monk known for playing the shakuhachi, were also effective, as the large "basket" hats traditionally worn by them concealed the head completely.


Ninja used a large variety of tools and weaponry, some of which were commonly known, but others were more specialized. Most were tools used in the infiltration of castles. A wide range of specialized equipment is described and illustrated in the 17th-century Bansenshūkai, including climbing equipment, extending spears, rocket-propelled arrows, and small collapsible boats.


Kuro shozoku ninja costume and waraji (sandals). The image of the ninja costume being black is strong. However, in reality, ninjas wore navy blue-dyed farmers' working clothes, which were also believed to repel vipers.
Gappa travel cape and zunin with kusari armor
Antique Japanese gappa (travel cape) and cloth zukin (hood) with kusari (chain armour) concealed underneath

While the image of a ninja clad in black garb (shinobi shōzoku) is prevalent in popular media, there is no hard evidence for such attire. It is theorized that, instead, it was much more common for the ninja to be disguised as civilians. The popular notion of black clothing may be rooted in artistic convention; early drawings of ninja showed them dressed in black to portray a sense of invisibility. This convention may have been borrowed from the puppet handlers of bunraku theater, who dressed in total black in an effort to simulate props moving independently of their controls. However, it has been put forward by some authorities that black robes, perhaps slightly tainted with red to hide bloodstains, was indeed the sensible garment of choice for infiltration.

Clothing used was similar to that of the samurai, but loose garments (such as leggings) were tucked into trousers or secured with belts. The tenugui, a piece of cloth also used in martial arts, had many functions. It could be used to cover the face, form a belt, or assist in climbing.

The historicity of armor specifically made for ninja cannot be ascertained. While pieces of light armor purportedly worn by ninja exist and date to the right time, there is no hard evidence of their use in ninja operations. Depictions of famous persons later deemed ninja often show them in samurai armor. There were lightweight concealable types of armour made with kusari (chain armour) and small armor plates such as karuta that could have been worn by ninja including katabira (jackets) made with armour hidden between layers of cloth. Shin and arm guards, along with metal-reinforced hoods are also speculated to make up the ninja's armor.


Ninpiden kuroro kagi breaker
A page from the Ninpiden, showing a tool for breaking locks

Tools used for infiltration and espionage are some of the most abundant artifacts related to the ninja. Ropes and grappling hooks were common, and were tied to the belt. A collapsible ladder is illustrated in the Bansenshukai, featuring spikes at both ends to anchor the ladder. Spiked or hooked climbing gear worn on the hands and feet also doubled as weapons. Other implements include chisels, hammers, drills, picks, and so forth.

The kunai was a heavy pointed tool, possibly derived from the Japanese masonry trowel, which it closely resembles. Although it is often portrayed in popular culture as a weapon, the kunai was primarily used for gouging holes in walls. Knives and small saws (hamagari) were also used to create holes in buildings, where they served as a foothold or a passage of entry. A portable listening device (saoto hikigane) was used to eavesdrop on conversations and detect sounds.

A line reel device known as a Toihikinawa (間引縄 / probing pulling rope) was used in pitch dark for finding the distance and route of entry.

The mizugumo was a set of wooden shoes supposedly allowing the ninja to walk on water. They were meant to work by distributing the wearer's weight over the shoes' wide bottom surface. The word mizugumo is derived from the native name for the Japanese water spider (Argyroneta aquatica japonica). The mizugumo was featured on the show MythBusters, where it was demonstrated unfit for walking on water. The ukidari, a similar footwear for walking on water, also existed in the form of a flat round bucket, but was probably quite unstable. Inflatable skins and breathing tubes allowed the ninja to stay underwater for longer periods of time.

Goshiki-mai (go, five; shiki, color; mai, rice) colored (red, blue, yellow, black, purple) rice grains were used in a code system, and to make trails that could be followed later.

Despite the large array of tools available to the ninja, the Bansenshukai warns one not to be overburdened with equipment, stating "a successful ninja is one who uses but one tool for multiple tasks".


Although shorter swords and daggers were used, the katana was probably the ninja's weapon of choice, and was sometimes carried on the back. The katana had several uses beyond normal combat. In dark places, the scabbard could be extended out of the sword, and used as a long probing device. The sword could also be laid against the wall, where the ninja could use the sword guard (tsuba) to gain a higher foothold. The katana could even be used as a device to stun enemies before attacking them, by putting a combination of red pepper, dirt or dust, and iron filings into the area near the top of the scabbard, so that as the sword was drawn the concoction would fly into the enemy's eyes, stunning him until a lethal blow could be made. While straight swords were used before the invention of the katana, there's no known historical information about the straight ninjatō pre-20th century. The first photograph of a ninjatō appeared in a booklet by Heishichirō Okuse in 1956. A replica of a ninjatō is on display at the Ninja Museum of Igaryu.

A pair of kusarigama, on display in Iwakuni Castle

An array of darts, spikes, knives, and sharp, star-shaped discs were known collectively as shuriken. While not exclusive to the ninja, they were an important part of the arsenal, where they could be thrown in any direction. Bows were used for sharpshooting, and some ninjas' bows were intentionally made smaller than the traditional yumi (longbow). The chain and sickle (kusarigama) was also used by the ninja. This weapon consisted of a weight on one end of a chain, and a sickle (kama) on the other. The weight was swung to injure or disable an opponent, and the sickle used to kill at close range.

Explosives introduced from China were known in Japan by the time of the Mongol Invasions in the 13th century. Later, explosives such as hand-held bombs and grenades were adopted by the ninja. Soft-cased bombs were designed to release smoke or poison gas, along with fragmentation explosives packed with iron or ceramic shrapnel.

Along with common shinobi buki (ninja weapons), a large assortment of miscellaneous arms were associated with the ninja.Some examples include poison, makibishi (caltrops), shikomizue (cane swords), land mines, fukiya (blowguns), poisoned darts, acid-spurting tubes, and teppo jutsu (firearms). The happō, a small eggshell filled with metsubushi (blinding powder), was also used to facilitate escape.

Legendary abilities

Superhuman or supernatural powers were often associated with the ninja with a style of Japanese martial arts in ninjutsu. Some legends include flight, invisibility, shapeshifting, teleportation, the ability to "split" into multiple bodies (bunshin), the summoning of animals (kuchiyose), and control over the five classical elements. These fabulous notions have stemmed from popular imagination regarding the ninja's mysterious status, as well as romantic ideas found in later Japanese art of the Edo period. Magical powers were rooted in the ninja's own misinformation efforts to disseminate fanciful information. For example, Nakagawa Shoshunjin, the 17th-century founder of Nakagawa-ryū, claimed in his own writings (Okufuji Monogatari) that he had the ability to transform into birds and animals.

Perceived control over the elements may be grounded in real tactics, which were categorized by association with forces of nature. For example, the practice of starting fires to cover a ninja's trail falls under katon-no-jutsu ("fire techniques"). By dressing in identical clothing, a coordinated team of ninjas could instill the perception of a single assailant being in multiple locations.

Actor portraying Nikki Danjō, a villain from the kabuki play Sendai Hagi. Shown with hands in a kuji-in seal, which allows him to transform into a giant rat. Woodblock print on paper. Kunisada, 1857.

The ninja's adaption of kites in espionage and warfare is another subject of legends. Accounts exist of ninja being lifted into the air by kites, where they flew over hostile terrain and descended into, or dropped bombs on enemy territory. Kites were indeed used in Japanese warfare, but mostly for the purpose of sending messages and relaying signals. Turnbull suggests that kites lifting a man into midair might have been technically feasible, but states that the use of kites to form a human "hang glider" falls squarely in the realm of fantasy.


Kuji-kiri is an esoteric practice which, when performed with an array of hand "seals" (kuji-in), was meant to allow the ninja to enact superhuman feats.

The kuji ("nine characters") is a concept originating from Taoism, where it was a string of nine words used in charms and incantations. In China, this tradition mixed with Buddhist beliefs, assigning each of the nine words to a Buddhist deity. The kuji may have arrived in Japan via Buddhism, where it flourished within Shugendō. Here too, each word in the kuji was associated with Buddhist deities, animals from Taoist mythology, and later, Shinto kami. The mudrā, a series of hand symbols representing different Buddhas, was applied to the kuji by Buddhists, possibly through the esoteric Mikkyō teachings. The yamabushi ascetics of Shugendō adopted this practice, using the hand gestures in spiritual, healing, and exorcism rituals. Later, the use of kuji passed onto certain bujutsu (martial arts) and ninjutsu schools, where it was said to have many purposes. The application of kuji to produce a desired effect was called "cutting" (kiri) the kuji. Intended effects range from physical and mental concentration, to more incredible claims about rendering an opponent immobile, or even the casting of magical spells. These legends were captured in popular culture, which interpreted the kuji-kiri as a precursor to magical acts.

Foreign ninja

On February 25, 2018, Yamada Yūji, the professor of Mie University and historian Nakanishi Gō announced that they had identified three people who were successful in early modern Ureshino, including the ninja Benkei Musō (弁慶夢想). Musō is thought to be the same person as Denrinbō Raikei (伝林坊頼慶), the Chinese disciple of Marume Nagayoshi. It came as a shock when the existence of a foreign samurai was verified by authorities.

Famous people

Many famous people in Japanese history have been associated or identified as ninja, but their status as ninja is difficult to prove and may be the product of later imagination. Rumors surrounding famous warriors, such as Kusunoki Masashige or Minamoto no Yoshitsune sometimes describe them as ninja, but there is little evidence for these claims.

Some well known examples include:

Kumawakamaru by kuniyoshi - 24 paragons of filial piety
Kumawakamaru escapes his pursuers by swinging across the moat on a bamboo. Woodblock print on paper. Kuniyoshi, 1842–1843.
  • Kumawakamaru (13th–14th centuries): a youth whose exiled father was ordered to death by the monk Homma Saburō. Kumakawa took his revenge by sneaking into Homma's room while he was asleep, and assassinating him with his own sword. He was son of a high counselor to Emperor Go-Daigo, not ninja. The yamabushi Daizenboh who helped Kumawakamaru's revenge was Suppa, a kind of ninja.
  • Kumawaka (the 16th century): a suppa (ninja) who served Obu Toramasa (1504– 1565), a vassal of Takeda Shingen.
  • Yagyū Munetoshi (1529–1606): a renowned swordsman of the Shinkage-ryū school. Muneyoshi's grandson, Jubei Muneyoshi, told tales of his grandfather's status as a ninja.
  • Hattori Hanzō (1542–1596): a samurai serving under Tokugawa Ieyasu. His ancestry in Iga province, along with ninjutsu manuals published by his descendants have led some sources to define him as a ninja. This depiction is also common in popular culture.
  • Ishikawa Goemon (1558–1594): Goemon reputedly tried to drip poison from a thread into Oda Nobunaga's mouth through a hiding spot in the ceiling, but many fanciful tales exist about Goemon, and this story cannot be confirmed.
  • Fūma Kotarō (d. 1603): a ninja rumored to have killed Hattori Hanzō, with whom he was supposedly rivals. The fictional weapon Fūma shuriken is named after him.
  • Mochizuki Chiyome (16th century): the wife of Mochizuke Moritoki. Chiyome created a school for girls, which taught skills required of geisha, as well as espionage skills.
  • Momochi Sandayū (16th century): a leader of the Iga ninja clans, who supposedly perished during Oda Nobunaga's attack on Iga province. There is some belief that he escaped death and lived as a farmer in Kii Province. Momochi is also a branch of the Hattori clan.
  • Fujibayashi Nagato (16th century): considered to be one of three "greatest" Iga jōnin, the other two being Hattori Hanzō and Momochi Sandayū. Fujibayashi's descendants wrote and edited the Bansenshukai.
  • Katō Danzō (1503–1569): a famed 16th-century ninja master during the Sengoku period who was also known as "Flying Katō".
  • Tateoka Doshun (16th century): a purported Iga ninja during the Sengoku period.
  • Karasawa Genba (16th century): a samurai of the Sengoku period, in the 16th century of the common era, who served as an important retainer of the Sanada clan.
  • Wada Koremasa (1536–1571): a powerful Kōka samurai ninja who in 1568 allied with the Ashikaga shogunate and Oda Nobunaga, at which point he relocated to Settsu Province.
  • Shimotsuge no Kizaru (16th century): an influential Iga ninja who in 1560 successfully led an attack on Tōichi Castle.
  • Takino Jurobei (16th century): The commander of some of the final resistance against Oda Nobunaga in his invasion of Iga. Momochi Sandayu, Fujibayashi Nagato no Kami, and Hattori Hanzō served as his officers.


Related pages

See also

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