Ninja
Ninja, also known as “Shinobi” or “Kusa (glass)”, are low-ranking combatants who try to avoid detection. Some books from the Edo period consider the ninja to be spies. However, not only gather information about the enemy, but also take the enemy by surprise on the battlefield. Although the name Ninja is familiar overseas, the custom of reading the character for “忍者” as “ninja” was not introduced until after the Asia-Pacific War. Incidentally, when the character for “忍者(ninja)” appears in old documents, it is read as “Shinobinono” ( Yuji Yamada, “忍者の歴史” and others).Duties of the Ninja
The ninja’s duties included ① searching for information in times of peace, ② soldiering to find out the enemy’s situation and terrain, ③ surprise attacks, and ④ guarding in times of peace (or war). Since there were few wars in the Edo period, ① and ④ were the main duties (Yoshiki Takao, “忍者の末裔 江戸城に勤めた伊賀者たち”).
Iga-mono and Koka-mono (Iga and Koka ninja)
Iga (western part of Mie Prefecture) and Koka (southern part of Shiga Prefecture) are famous as a land where many excellent ninja were brought into the world. The reason for this is that the area was surrounded by mountains, which prevented large groups of warriors from entering the area and attracted many small groups of samurai (地侍jizamurai) (“Bansenshukai”). It is thought that internal struggles among these groups led to the birth of the ninja, who were employed to surprise the enemy or to spread false information. From the Kamakura period to the Muromachi period, many warrior groups known as Akuto (samurai who rebelled against the shogunate and lords of manors) in Iga, probably due to internal conflicts among groups of local samurai in the Warring States period.(Yoshiki Takao, “伊賀者の歴史を辿る”, in “忍者学講義”, edited by Yuji Yamada)
