A ninja (Japanese: 忍者; [ɲiꜜɲdʑa]) or shinobi (Japanese: 忍び; [ɕinobi]) was a spy and infiltrator in pre-modern Japan. The functions of a ninja included siege and infiltration, ambush, reconnaissance, espionage, deception, and later bodyguarding. Antecedents may have existed as early as the 12th century. There is little evidence that they were assassins. In the unrest of the Sengoku period, jizamurai families, that is, elite peasant-warriors, in Iga Province and the adjacent Kōka District formed ikki – "revolts" or "leagues" – as a means of self-defense.
https://en.wikipedia.org/wiki/Ninja
A ninja (Japanese: 忍者; [ɲiꜜɲdʑa]) or shinobi (Japanese: 忍び; [ɕinobi]) was a spy and infiltrator in pre-modern Japan. The functions of a ninja included siege and infiltration, ambush, reconnaissance, espionage, deception, and later bodyguarding. Antecedents may have existed as early as the 12th century. There is little evidence that they were assassins. In the unrest of the Sengoku period, jizamurai families, that is, elite peasant-warriors, in Iga Province and the adjacent Kōka District formed ikki – "revolts" or "leagues" – as a means of self-defense.
