ninja

Kunoichi, meaning a female ninja, supposedly came from the characters くノ一 ( pronounced ku, no and ichi ), which make up the three strokes that form the kanji for " woman " ( 女 ).

In the West, the word ninja became more prevalent than shinobi in the post-World War II culture, possibly because it was more comfortable for Western speakers.

In English, the plural of ninja can be either unchanged as ninja, reflecting the Japanese language's lack of grammatical number, or the regular English plural ninjas.

Despite many popular folktales, historical accounts of the ninja are scarce.

Historian Stephen Turnbull asserts that the ninja were mostly recruited from the lower class, and therefore little literary interest was taken in them.

Historian Kiyoshi Watatani states that the ninja were trained to be particularly secretive about their actions and existence:

The title ninja has sometimes been attributed retrospectively to the semi-legendary 4th century prince Yamato Takeru.

It was around this time that the word shinobi appeared to define and clearly identify ninja as a secretive group of agents.

The ninja emerged as mercenaries in the 15th century, where they were recruited as spies, raiders, arsonists and even terrorists.

The ninja families were organized into larger guilds, each with their own territories.

The plains of Iga Province | Iga, nested in secluded mountains, gave rise to villages specialized in the training of ninja.

From these regions, villages devoted to the training of ninja first appeared.

A distinction is to be made between the ninja from these areas, and commoners or samurai hired as spies or mercenaries.

Unlike their counterparts, the Iga and Kōga clans produced professional ninja, specifically trained for their roles.

These professional ninja were actively hired by daimyos between 1485 and 1581, until Oda Nobunaga invaded Iga province and wiped out the organized clans.

Following the Battle of Okehazama in 1560, Tokugawa employed a group of eighty Kōga ninja, led by Tomo Sukesada.

The account of this assault is given in the Mikawa Go Fudoki, where it was written that Kōga ninja infiltrated the castle, set fire to its towers, and killed the castellan along with 200 of the garrison.

The Kōga ninja are said to have played a role in the later Battle of Sekigahara ( 1600 ), where several hundred Kōga assisted soldiers under Torii Mototada in the defence of Fushimi Castle.

In 1614, the initial " winter campaign " at the Siege of Osaka saw the ninja in use once again.

Miura Yoemon, a ninja in Tokugawa's service, recruited shinobi from the Iga region, and sent 10 ninja into Osaka Castle in an effort to foster antagonism between enemy commanders.

During the later " summer campaign ", these hired ninja fought alongside regular troops at the Battle of Tennōji.

A final but detailed record of ninja employed in open warfare occurred during the Shimabara Rebellion ( 1637 – 1638 ).

The Kōga ninja were recruited by shogun Tokugawa Iemitsu against Christian rebels led by Amakusa Shirō, who made a final stand at Hara Castle, in Hizen Province.