Problem with Ninjas is that people try to put one definition over something that cannot be defined in one way. You will see people arguing whether Ninjas were assassins or spies or etc. Well, the sad fact for people like them is that there is hardly any historical evidence that Ninjas were involved in assassinations. The Japanese Daimyos lived in danger of assassination all the time, so they did not let strangers approach them in any way. Forget all the images of Ninjas dressed in black sneaking in. The soldiers were not idiots. The castle walls were painted white to spot any intruders in night, so good luck trying to sneak in with that black outfit. In reality, they dressed up like a plain pedestrian to avoid guards’ suspicious eyes. So the Agent 47 is in fact the closest thing to the modern Ninja? Probably. Except all the assassination parts…
“Realistic” Ninjas were… well, they were information brokers. Hungry vagabonds hearing rumours and selling the information at the highest bidders. That was the case for the most Ninjas. Even Japanese historical TV show admit this and described Ninjas as modern businessmen selling information to their clients. But you would be wondering about all the training manuals and secret scrolls. Well, here’s the reason why Ninjas became hard thing to define.
There were Iga and Koga, who were “professional” information brokers. They did train to acquire spying techniques, and they were exceptions. In fact, Koga clan was a remnant of low ranking Samurais, and they fought at war as soldiers too. So much for the stealthy assassin. The secret scrolls? They were lucky charms. Ninjas did not believe they would work in real life, but people under high pressure need something to keep them calm.
So the realistic Ninjas were secret agents, not mystic assassins. And their qualities varied. Few were highly trained spies, while the others were nothing but rogues. And they were never assassins. You may wonder where the images of Ninja assassins come from.
The modern stereotypes of Ninjas were established by novelists, such as Futaro Yamada and Ryotaro Shiba. In fact, the modern depiction of Ninjas, who use martial arts and “nin-jitsu” was invented by Futaro Yamada, in his work Koga Ninpo Cho or Kouga Ninja Scrolls. This work was later adapted as manga and anime series Basilisk. This became popular fantasy among readers, and many manga artists and novelists used images created by Yamada, and sometimes “improved” it.
The image of Ninja assassins were popularized by theatres and Ryotaro Shiba’s novel, The Castle of owls. But you have to realize that it was still the popular fiction, not the actual history that depicts Ninjas as assassins. Actually, the Ninja’s popular image as men dressed in black came from theatres too. They dressed in black to “hide” from the audiences. Interestingly, Dracula’s cape was added in the theatre versions for the same reason.
Fictional Ninjas were naturally popular; it could be considered distinctively “Japanese”, and manga artists such as Sanpei Shirato added social/political contexts to add depth to the Ninja mangas. In Shirato’s works, Ninjas became representative of socialist messages, who fought against Samurais who represented high class or capitalists. Shirato’s work was the first Ninja media to feature “Izuna Otoshi”, one of the most famous Ninja techniques. With masters like Shirato, Ninja media thrived more.
When Ninja media was exported to the West, they sold such “modern Ninja” rather than realistic one. After all, “fictional Ninja” was the popular and “sellable” merchandise. Soon, Ninjas became oriental icons. Thanks to the diverse Ninja media, Ninja characters became versatile; you want martial artist? Add Ninjas. You want sorcerer? Add Ninjas with ninjitsu. You want assassin? Add Ninjas. You want something oriental and mystic? Add Ninjas. They were extremely easy to design too – wrap their faces in certain way, everyone recognize them as Ninja. Such versatility helped Ninjas to become recognizable, and fed off the fantasy of audiences outside Japan.
So here is the problem. The various images of Ninjas, mostly fictional, were mixed up in the popular media, and it became hard to separate. People are mesmerized by the glamour of stealthy assassin, yet never had a chance to learn about the historical facts (because foreign histories rarely sell unless it is European). Japanese continue to sell the fictional depiction of Ninjas because they sell really well. So many images are distant from what Ninjas were, yet people are trying to pinpoint one definite version of Ninja. And whatever they believe Ninja to be, they are quite far away from historical versions thanks to all the popular media. Even among historical Ninjas, there were so many different types. So how can you define Ninja? My best effort would be “spies in historical Japan who became popularized as something different from what they were throughout the history”.
In a way, Ninjas succeeded in disguising their true identity. People are mesmerized by the fictional images, and not many can see through this deception.
While historians suffer from headaches, popular fictions thrive. That’s how it goes with many “popular histories”, such as Dracula, Vikings, Cowboys, and Samurais.