Last week I went to Tsu city, a prefectural capital, for the first time to see an exhibition about ninjas in the Mie Prefectural Museum. I was curious about ninjas, because there was a big difference between ninjas as a comic book character and the true face of historical ninjas. The former one gave me a humorous image but the latter one made me realize that the ninja was a spy.
We can find the earliest descriptions of ninjas written in 1338. Ieyasu who dominated Japan during the early Edo Period, was helped by ninja in 1582. It became a springboard to get a job as a security guard around Edo castle.
The best known ninjas are “Iga Ninja” who lived in my city. There were these kinds of ninja in Kumamoto, Kagoshima, Shimane, Hiroshima, Osaka, Wakayama, Nagano, Yamanashi, Niigata, Kanagawa, Miyagi, Iwate and Aomori.
They improved their concentration by staring at a candle flame. And they train themselves by sitting alone in a dark place for 35 days, before infiltration to improve their eyesight in darkness. Also they trained their hearing by having someone drop needles behind them and guessing how many needles have fallen. It helped to perceive the number of enemies and to identify a specific person’s voice in a crowd. They trained their sense of smell to guess the person’s profession, too.
Amazingly, they could distinguish between REM sleep and non-REM sleep among the people they infiltrated, to know the optimal time to sneak into enemy territory. And to remember secret information, they connect it to their emotions. They could also predict the weather.
After seeing this exhibition, my image of ninjas changed from a specialist to a generalist. They were security generalists.