A common claim among ‘ninja’ historians is that there existed female shinobi known as kunoichi, who specialized in infiltration by means of feminine wiles. Their skills supposedly ranged from pretending to be maids or dancers to gather intelligence, to seducing a high-value target with a view to post-coital assassination.
References to kunoichi are easy to find. They’re there in the classics of the published ‘ninja’ literature, like Andrew Adams:
These networks of spies also included female ninja called kunoichi. A feudal-age Mata Hari was often a ravishing beauty plucked from among the ninja clans or recruited from sympathetic families in enemy country. Her main task was to use her feminine charms to draw vital secrets from enemy leaders. Although she was taught to handle ninja weapons, her main assassination tool was a long, lethal-looking hairpin innocently concealed in her coiffure.1
and Donn Draeger:
When any one particular warlord proved to be unapproachable by normal means the ninja assigned to assassinate him might enlist the services of a female ninja, usually a beautiful and talented dancer. It would be arranged for her to eventually be requested to dance at the enemy lord’s castle. So great would be her physical beauty that the lord could not resist her charms and would order her to occupy his bed.2
Kunoichi pop up frequently in online English-language ‘ninja’ lore as well (like, here, here, here, and here, for instance), and they’re also staple characters in a lot of obviously fictional ‘ninja’ media, like the mega-hit anime Naruto and Japanese video games such as Dead or Alive. Much of the time the kunoichi figure is heavily sexualized, and in fact it’s not that uncommon to find kunoichi as characters in straight-up porn (linked page itself is probably SFW, but anything you click on thereafter won’t be).
What’s the Deal with the Ninja Chicks?
Let me summarize the best and most up-to-date scholarship on kunoichi, then:
They didn’t exist. Like, at all.
There appears to be no solid historical evidence to support the claim that there were female shinobi. The closest thing is a couple of fairly ambiguous passages in the 17th century ‘ninja’ manual Bansen shūkai (below, BSSK) which do use the term kunoichi and suggest that women can be used in infiltration operations, but as with a lot of BSSK there’s no evidence this happened outside of the imagination of the author. The bulk of kunoichi lore derives from Japanese pulp novels and movies from the late 1950s and early 1960s onward, mis-recognized as fact by a lot of historical writers who were either fabulists or not very good at their jobs.
If you’ve been reading this newsletter over the last few months, this’ll be a familiar pattern. We’ve seen it before with the ‘ninja-shuriken’ connection, for instance, since there’s no evidence shinobi used star-shaped throwing weapons or were even associated with them. Rather, the ‘ninja-shuriken’ connection came about through fictional depictions in postwar movies and novels which were then misrepresented as historical fact.
Yoshimaru Katsuya, “What is a Kunoichi?”
I’ve been extremely critical of a lot of ‘ninja’ history, but there is good stuff out there, and one of the things I want to do in this newsletter is to make it accessible. There are some insightful scholars working in Japanese right now who publish stuff that the English-speaking public would love to see but which nobody ever translates, so it remains out of reach.
That’s where I come in, since making Japanese-language scholarship accessible to English-speaking audiences is one of the value propositions here (as the corporate types say). I can’t be in the business of translating entire articles, unfortunately, both for copyright reasons and because I simply do not have the time. What I’ll do with the scholarship I discuss is to summarize the main points and arguments, translating only key passages so that I stay within the bounds of what’s legally acceptable.
We’ll start with the work of Yoshimaru Katsuya of the Ninja Research Center at Mie University. The NRC is a relatively recent creation, and it’s in Mie Prefecture because part of Mie used to be Iga Province, supposedly the heartland of the historical shinobi. Whatever the truth of the Iga-shinobi thing, it’s been a major element in postwar Mie Prefecture’s regional identity and tourist promotion strategies. Hell, there’s even a Mie Prefecture sake called Ninja.
Yoshimaru’s “What is a Kunoichi?” (Kunoichi to wa nani ka), our topic for today, was published in the 2017 edited volume The Birth of the Ninja (Ninja no tanjō).3 Its central question is really how the fictional image of the kunoichi we have now came about; it is, as we’ll see, largely dismissive of kunoichi as historical reality.
Yoshimaru begins his discussion as follows:
In November of 2014, accompanied by the 21st Grand Master of Koga-ryū ninjutsu Kawakami Jin’ichi, I took part in a series of lectures on and demonstrations of ninjutsu in Barcelona, Madrid, and Rome. In the Q&A that followed, the question “Were there any female ninja?” would always come up.
And the answer came back the same each time: “Unfortunately, there were no female ninja in premodern times.”
The reason for this is quite simple. There is no record of any women among the ranks of the shinobi, those warriors who, in times of peace slipped into enemy territory to scout and gather intelligence; or who, in times of war, would, in addition to their scouting activities, also steal into enemy bases and castles to carry out acts of arson and assassination. Nor does one find any evidence for the activities of female ninja with their own distinctive set of skills and training.4
This is about as direct and clear-cut as you can get. To the question “did female shinobi exist?”, Yoshimaru’s answer is a simple “no.”
‘Ninja’ enthusiasts might immediately object: what about Mochizuki Chiyo? You can read accounts of her in English-language media as a real-life female shinobi who worked for Takeda Shingen and controlled a network of female spies.5 That’s literally a perfect historical example of kunoichi, right?
Nope. As Yoshimaru argues elsewhere in the same book, the story of Mochizuki Chiyo (or Chiyome) as a female ‘ninja’ appears to be a 1970s fabrication.6 I’ll cover the apparently fabricated Mochizuki Chiyo story and Yoshimaru’s arguments in a separate post to follow.
Basically, Yoshimaru disposes of the notion of kunoichi as a real historical phenomenon in the first few paragraphs of the piece, after which he doesn’t really return to the question. He then goes on to explain what he’s really interested in exploring:
So, when was it that the historically non-existent female ninja made her appearance in the world of fiction? How is she depicted in the world of fiction, and how did she come to acquire what is now her standard form?7
In other words, Yoshimaru’s primary concern throughout the piece will be the kunoichi as a fictional figure and literary archetype. That is to say, the key question is how and when the figure of the female ‘ninja’ emerged in prose fiction and film, and how she came to take the form that we see her in nowadays.
Kunoichi was an Obscure Slang Term for ‘Woman,’ and did not mean ‘Female Ninja’
The starting point for Yoshimaru’s investigation, then, is to consider where the term kunoichi came from. The most common explanation is that the term derives from the fact that the kanji for ‘woman,’ which is 女 and usually read ‘onna,’ can be broken down into three smaller graphs: the hiragana く (ku), the katakana ノ (no), and the kanji 一 (ichi).8
Looking at premodern poetry and at 20th century slang dictionaries, Yoshimaru finds that the term kunoichi probably dates only to the Edo period (1600-1867), though even then it doesn’t seem to have been commonly used. As far as Yoshimaru can determine, in these contexts the term kunoichi did not mean ‘female ninja’ – rather, it seems to have been a semi-obscure or niche slang term for ‘women’ in general. I say “semi-obscure” because, as Yoshimaru points out, in the Edo period it would have been relatively unusual to write the kanji in its printed form of 女. Edo-period text was mainly printed via carved woodblocks, so the writing was quite often in a hand-written, semi-calligraphic style, not the clearly defined printed form we tend to use today.9
For that reason, the kanji 女 would have been more commonly written in calligraphic style, looking somewhat like the hiragana め. Even if you’re not familiar with Japanese, you can perhaps see below how the graph on the right could emerge as a version of the one of the left written with one or two brush-strokes:
Yoshimaru’s point is that for most readers, the word ‘woman’ was not consistently written in such a way as to clearly distinguish the individual elements of ku, no, and ichi. For that reason, it’s likely that the slang term kunoichi was not a common one in Edo-era Japan.
The Shinobi Connection: Bansen shūkai (Again)
If kunoichi was simply a slang term for ‘women,’ then where did the shinobi connection come from? Well, the earliest use of the term in the context of clandestine operations is our old friend the Bansen shūkai. If you aren’t already familiar with BSSK, it’s a collection of alleged shinobi wisdom compiled around 1676 and which surfaced in Japan in the 1930s. I’ve discussed BSSK and its issues at considerable length in an earlier series of posts, so I won’t re-cover the same ground here.
There are indeed two parts in BSSK where the term kunoichi is used, and both basically suggest that a shinobi can attempt to place women within an enemy household in order to help him gain access to the premises. One method suggested, for instance, is to place a woman within an enemy’s household (presumably as a servant), then have her ask for a chest of clothes to be brought in to the chambers of the lady of the house. That chest can have a false bottom, within which is concealed a male shinobi, and that’s how he gains entry to do his nefarious deeds.10
The second section, which Yoshimaru does not mention and which comes a little later in the text, also suggests that a woman can be sent into an enemy house ahead of time and then help other agents gain entry. The second passage also mentions that men are vulnerable to lust or greed, and high-ranking men particularly so, making this kunoichi technique likely to be effective.

It’s not entirely clear from context how to interpret the kunoichi passages in BSSK. We could certainly split hairs here over whether placing a woman in an enemy household in advance would count as a “female shinobi” or not. Yoshimaru appears to think not, since in discussing BSSK’s mention of kunoichi he interprets these as infiltration techniques “in which women are used; it does not mean that there were female ninja.”11
In other words, as Yoshimaru reads it, it seems that the idea here is that women were relatively minor participants rather than being highly trained agents or assassins themselves. This impression is perhaps confirmed by the first kunoichi passage in BSSK, which also states that women are, frankly, not very bright and so you have to be careful in selecting them for this type of operation.
As I said, we could argue about how to parse the BSSK’s mention of kunoichi - like, does the mention of men being vulnerable to lust imply that kunoichi were in fact the seductress-assassins of popular lore? Or does it just mean that an attractive woman would have an easier time being hired as a maid, and you should bear that in mind in your planning? This kind of discussion strikes me as pointless, though, because we have no reason to believe that anyone ever actually did what BSSK describes. Much as with shuriken, discussing how kunoichi were used is a waste of time when we have no evidence they were. And that’s the big problem - we have no corroboration from any other source than BSSK that what it describes happened.
Remember, also, that when it comes to the content of ‘ninja manuals’ like BSSK, we have no reliable way of distinguishing among real shinobi lore, stuff lifted from other military manuals, garbled second- and third-hand stuff, and outright fantasy or invention on the part of the authors. You can’t be presenting any specific passage as authentic shinobi practice unless you have some pretty damn good external evidence to support that claim.
Anyway, Yoshimaru gives BSSK fairly short shrift, a total of five lines in his piece, so it’s clear he isn’t that interested in the text overall. Most of the rest of the argument will center on depictions of female warriors and heroines in fictional works from the Edo period to the present day, so that’s where we’ll go next.
Andrew Adams, Ninja: The Invisible Assassins (1970; my copy 1973), p. 28. Kunoichi are mentioned again on p. 124, where Adams states that they “received the same rigorous training as their male counterparts.”
Donn Draeger, Ninjutsu (1971; my copy 1989), p. 54.
Yoshimaru, “Kunoichi to wa nani ka” in Yoshimaru, Yamada Yūji, eds., Ninja no tanjō (Bensei Shuppan, 2017), pp. 167-190. For those who may not be familiar, an “edited volume” is a book with lots of chapters by different people, overseen by one or two overall editors.
Yoshimaru, “Kunoichi to wa nani ka,” p. 167. Japanese: 二〇十四年十一月に、甲賀流伴党二十一代目宗家の川上仁一先生とともにバルセロナ・マドリード・ローマで忍者忍術講演・実演会を行った。演後の質疑応答で「女の忍者はいましたか」という質問がいずれも出た。「残念ながら、前近代には女の忍者はいません」とその都度答えてきた。理由は簡単である。平時に敵地侵入して偵察・情報収集を行い、戦争時には偵察の他、敵陣・敵城に侵入して放火・暗殺を行う「忍び」に女がいたという記録がないからである。特殊な忍術を身につけ活躍した女忍者の記録も見当たりもしない。
In the printed literature, she’s also mentioned in Hiroko Yoda and Matt Alt’s Ninja Attack! (Tuttle, 2012), p. 59.
Yoshimaru, “Kunoichi to wa nani ka,” p. 167. The article on Mochizuki Chiyo(me) 望月千代(女) is in the same book on pp. 281-287, entitled “Mochizuki Chiyome-den no kyomō” (‘The False Account of Mochizuki Chiyome’). Kyomō 虚妄 is a pretty harsh word in Japanese, implying not just being wrong but making groundless claims and/or deliberate lying.
Yoshimaru, “Kunoichi to wa nani ka,” p. 168.
You’ll also see the explanation in some quarters that kunoichi actually means “nine plus one,” because men have nine orifices in their body and women have ten, the tenth presumably being the vagina (?). I suppose it depends on what you count as ‘orifices.’ Yoshimaru finds that there is no evidence to support this idea, however (p. 168).
Yoshimaru, “Kunoichi to wa nani ka,” pp. 168-9.
Fujibayashi (?) ed., BSSK vol. 8, n.p. Original available here; it’s p. 11 by the NAJ ordering. For an English translation, see Minami, trans., and Cummins, ed., The Book of Ninja, p. 107.
Yoshimaru, “Kunoichi to wa nani ka,” pp. 169. Japanese:「くノ一」=「女」を使った術であって、女忍者がいたという意味ではない。