Ninpo is a group of related martial traditions that have developed in Japan since the ancient period (before the 12th century), and that have been combined in the modern period under one comprehensive martial system. This system includes the eighteen martial skills (bugei juhappan) for the common bushi (warrior), and another group of eighteen unconventional types of martial skills (ninja juhakkei) for special warfare. Another component of Ninpo, in addition to these thirty-six martial skills, is a unique world view, thought and philosophy, and esoteric practices. This world view emphasizes the defensive nature of Ninpo, and the need to have a compassionate heart.
The term "Ninpo"
The term "ninpo" is made of two characters. The first, "nin," literally means patience, perseverance, and stealth. The character itself is composed of two characters to have a blade placed over the heart/mind. There are a number of symbolic meanings to that. One, the blade forces the heart/mind to remain stealth in order to persevere. Another meaning is that the heart/mind should be as sharp and pure as the sword.
The second character, "ho," is philosophically more complicated thus more difficult to grasp, and has a strong Buddhist connotation. In modern Japanese this character is used for the word "law" (as in the legal system), but in the term "ninpo" it takes on the Buddhist meaning of the universal Buddhist Law. In Sanskrit the word Dharma (Jp. Law) has a deep and complex meaning, but it essentially means factors of existence on one level, ultimate reality on another level, and the Buddhist doctrines and thought on yet another level. The result of combining it with the first character "nin" produces a term ("ninpo") that could be understood as the ultimate and eternal reality of perseverance and stealth. However, one should not rigidly define or interpret Ninpo in one way, rather understand the depth of it in its various meanings.
Ninjutsu. The term ninjutsu literally means skills of perseverance, and is an historical (vis a vis historiographical) term. In the 17th century ninjutsu records (Bansenshukai, Ninpiden and Shoninki), their authors extensively use the word ninjutsu to refer to their martial tradition. Historically, ninjutsu is a general term for a variety of martial skills that share a common characteristics. These characteristics include the people who nurtured and developed ninjutsu, the combination of conventional and unconventional fighting methods, and the period when ninjutsu was most widely used, among other characteristics. Since I discuss the possible origins of ninjutsu in this essay on Ninpo and in my section on Ninpo history, in the following paragraphs I will focus on the martial skills that constitute ninjutsu.
It is possible to divide ninjutsu to four fundamental categories: taijutsu, ninki (weapons), heiho, and shugyo (religious practices). Taijutsu (lit. body skills) is unarmed fighting techniques divided into kosshijutsu, koppojutsu, dakentaijutsu, jutaijutsu, and taihenjutsu.
Ninjutsu weapons are rather numerous and include conventional weaponry such as short and long swords, naginata, and yari, among others. In addition, there is a large variety of unconventional weapons such as special bladed weapons, concealed weapons, collapsible ladders, floating devices, and many more. It is common among those who practice ninjutsu these days to think that in medieval Japan the goal was to master all aspects and all the techniques associated with ninjutsu. In fact, it was quite the contrary. The aim was at specialization rather than an overall mastership. It is important to remember that being born in medieval or early-modern Japan meant that oneีs future depended very much on the family in which one was born--even, or especially if the family did not belong to the samurai class. Thus, those warriors who were skilled in Ninjutsu only specialized in some aspect of ninjutsu, and functioned accordingly within their family. If we look at the famous Iga and Koga regions, we see a few tens of families within which there were the majority of family members who acquired just basic skills, those who specialized in the use of certain weapons or techniques, and those who led the families and specialized in strategy.
It is common among sincere Ninpo practitioners to blame the movie industry for creating a dark and evil image for the ninja. However, the movie industry only reflected and exaggerated a common Japanese view of Ninpo/Ninjutsu and ninja that have existed in Japan at least since the early-modern period (Tokugawa/Edo period 1600-1868). For a society that was divided and locked in distinct social classes, with little or no social mobility, a society that was highly regulated and conformed, anything that was out of the ordinary, or that did not conform to common knowledge, was subjected to fantastic portrayal. This was true not only for Ninjutsu but also in other areas where ignorance led to the creation of legends and superstitions. To illustrate how some of these fantastic legends were created, here are just a few examples:
1. The ninja could walk on water.
In Ninjutsu there are a number of devices to aid a warrior in crossing a water barrier. One such floating device was warn like sandals and allowed the warrior to "walk on water."
2. The ninja could apply super human powers and disappear out of enemy sight.
Disappearing techniques utilize surprise, technical body maneuverability, and the aid of blinding devices or techniques, to "super humanly disappear." For example, setting off small explosives to create a cloud of smoke, or simply throwing sand at the opponents eyes would provide a warrior the opportunity to hide. These techniques are now common in any modern soldier's basic training. Using a small smoke grenade would allow the soldier to retreat behind cover, or a smoke producing device would allow a tank to disappear behind a smoke screen and drive to safety behind a ramp.
3. The ninja were hired assassins.
Assassinations, betrayals and deceptions in the Warring States period (Sengoku period, 1467-1573) were as common as acts of loyalty. It was a period of disunity when warriors at all levels were looking after their own interests. It was during that time that warriors skilled in special warfare were highly desirable and often utilized. They were the secret agents of the time, and were a crucial component of a daimyo's army. It was in that period that Ninjutsu was most often utilized in the context of covert tactics and information gathering. It is important to remember that the betrayal was done by low level samurai and the highest generals alike (for example, the betrayal of Oda Nobunaga by Akechi Mitsuhide).
4. The ninja were spies.
Indeed those who were skilled in ninjutsu were proficient in surveillance techniques, but it is a common mistake to view these warriors as professional spies who were groomed since childhood to serve as such. It would be much more accurate to view them as warriors whose skills included surveillance techniques, among many other skills that they have acquired. Consequently, these warriors who were skilled in ninjutsu proved useful in many occasions, as information gatherers or even massive fighting forces that joined the battlefield. It is important to consider these warriors' perspective on their own life and activity. From that we learn that these warriors were associated with certain regions and communities that were often trying to survive the bloody years of the Sengoku period, or survive class struggles of the early modern period.
In conclusion, those warriors who applied unusual warfare tactics, techniques, and devices were many years ahead of their time. All those special skills that today can be explained logically, were a frightening mystery for the common people of earlier periods. But the legends remained and over the years became folklore, which is almost impossible to dispel. In other words, the belief in legends is so deep that these legends became an historical fact. The truth remains, though, that warriors in Japanese history who applied Ninjutsu were not super-human assassins for hire, rather a group of people who were not confined to common concepts and rules and developed a wider, more effective form of fighting skills.