It is considered that the secret ninja clans originally appeared in Japan at the same time as the samurai class in IX-XII centuries. The prototype of the ninja sect considered yamabushi, Japanese mountain ascetic hermits. Yamabushi encouraged heavy and grueling training among their adherents. For centuries they carefully maintained collected knowledge in the fields of medicine, chemistry, and astrology. Yamabushi were adherents of complete fusion with nature. Initially secret schools of ninjutsu had nothing to do with military. Neither the technique of preparation nor their philosophy had anything to do with it. However, over time some changes occurred. 

    Traditionally ninja played the role of a covert agent or mercenary in feudal Japan. The functions of the ninja included espionage, sabotage, infiltration, and assassination, and open combat in certain situations.

    Ninja’s family members were a tightly knit groups that were integrated into larger groups called clans. 

    The covert methods of waging war contrasted the ninja with the samurai, who observed strict rules about honor and combat. In accordance with them samurai tried to fight with dignity and find the best way to prepare themselves for death. Ninja professed completely the opposite philosophy. It was important for the ninja to complete the task. As their main task was intelligence service, so it was critical for them to survive at any cost in order to achieve success of the task’s implementation. There were no forbidden actions, no existing moral, religious and ethical limitations in the methods of warfare for ninjas. 

    Camouflage ninja suit 

    While the image of a ninja clad in black garb is prevalent in popular media, there is no written evidence for such a costume. Instead, it was much more common for the ninja to be disguised as civilians. During the daytime ninja wore casual clothes, which allowed them to merge with the crowd. At nighttime their costumes were reddish-brown, ash, yellow-brown or dark gray colors, which allowed them to fully merge with the night mist, while completely black suit stood out in these conditions.