Most Westerners think of ninjas as black-masked men with swords who appear from the shadows and strike without warning.

But not all ninja assassins were male, and not all of them walked in shadow.

Female ninjas, known as kunoichi, formed an important part of medieval shinobi clans. Like their male counterparts, kunoichi trained in combat, disguise, and stealth, though their missions and function differed from those of male shinobi in several important ways.

Disguises and Tactics

Shinobi (which is the Japanese pronounciation of the characters Westerners read as “ninja”) worked as spies as well as assassins. All shinobi could kill in the line of duty, and many did, but others acted as covert agents—often deep undercover in enemy territory.

Medieval Japan was ruled and dominated by men of the samurai class. Samurai rarely trusted strangers, but often made exceptions for women, either because of their beauty or because the woman filled a “harmless” social role (a maid, for example). Kunoichi frequently posed as performers, courtesans, or servants. In these disguises, kunoichi infiltrated temples, castles, and fortresses, either to gather information or to strike at well-protected targets male assassins could not reach.

A male shinobi might assume the role of a samurai retainer or an artisan, but those positions seldom allowed the assassin unfettered access to his target. Samurai lived well-defended lives. Assassinations by male ninja often took the form of clandestine (usually nocturnal) missions, a medieval form of “seek and destroy.”

By contrast, a kunoichi could gain her target’s trust until he allowed her intimate access, at which point she could attack—when both his pants and his guard were down.

Shinobi training for both genders focused on utilizing the ninja’s personal strengths to best advantage. In medieval Japan, where women were often prized for beauty rather than skill, a kunoichi’s beauty was one of her most valuable—and deadly—weapons.

But that doesn’t mean the female ninja depended exclusively on her looks. In combat, kunoichi were just as deadly, and as well-trained, as any other shinobi.

Special Weapons

Like their male counterparts, kunoichi trained with a variety of weapons. Most knew how to use a sword, though female ninjas usually specialized in close hand-to-hand combat—which meant a preference for daggers, garrotes, poisons, and specialty items like bladed fans and claw-like finger extensions known as neko-te.

Neko-te, in particular, were used almost exclusively by kunoichi. The weapon consists of leather finger sheaths topped with sharpened metal “claws.” The sheaths slipped over the end of the wearer’s fingers, giving the kunoichi a set of lethal, tiger-like claws that measured from one to three inches in length. Many women poisoned the metal claws for added effect.

Neko-te slipped on in an instant but disappeared just as quickly into a pocket or the sleeve of a kimono, facilitating surprise attacks and helping the kunoichi avoid discovery.

Visibility—or lack thereof

In some ways, kunoichi inspired more fear than their masculine counterparts because of their ability to mimic different types of women that samurai often regarded as harmless. Samurai guards could watch the roof and patrol the corridors of a warlord’s castle. Lanterns and watchmen on the walls could stop a shinobi from sneaking in unseen. But kunoichi didn’t sneak inside under cover of darkness and they rarely killed their targets right away. A kunoichi took her time, earning the target’s trust and often becoming a part of his household. From that trusted position, she passed information to his enemies or struck when he let his defenses down.

When it came to infiltrating samurai strongholds, the kunoichi’s ability to adopt the role of a mistress or servant had obvious advantages over the disguises a male could use. High-ranking samurai chose retainers from among their relatives and trusted associates, making it harder for male shinobi to reach a position from which he could spy or strike at the target effectively. A woman, on the other hand, needed only to appeal to the target’s natural attractions, particularly when she approached in the guise of a courtesan or professional entertainer.

Then, as now, sex sells … and dangerous sex can kill.

Respect

Both male and female ninjas operated as undercover agents, some so deeply in disguise that they could never return to their former lives. Some assignments were permanent—to spy on a target as long as he lived or until the shinobi’s identity came to light. Other assignments took the form of suicide missions—to infiltrate and strike the target, even though the shinobi would die in the process.

Kunoichi weren’t exempt from suicide missions or deep undercover assignments. In most ways, they acted and were treated the same as their masculine counterparts, though with tactics, assignments, and weapons suited to their differing strengths. In medieval Japan, this wasn’t considered “discrimination”—just a proper exploitation of tactical advantage.

Modern Westerners might not recognize a killer in a courtesan’s dress, but in samurai Japan, a wise man knew that a dagger often lurked in a beautiful woman’s bladed fan.

Leading image via Getabo at Deviant Art. Kamakura-era courtesan via The Costume Museum. Neko-te via author's website. Attack scene via Fischer Art History.

Susan Spann is a transactional attorney and former law school professor whose practice focuses on publishing law and business. Claws of the Cat, her debut shinobi mystery featuring ninja detective Hiro Hattori, releases on July 16, 2013, from Minotaur Books. Susan has a deep interest in Asian culture and has studied Mandarin and Japanese. Her hobbies include Asian cooking, fencing, traditional archery, martial arts, rock climbing, and horseback riding, and she keeps a marine aquarium where she raises seahorses and rare corals. You can find Susan on Twitter @SusanSpann.