Kunoichi

A is a female ninja or practitioner of ninjutsu ("ninpo"). During the feudal period of Japan, ninjas were used as killers, spies and messengers. The training of kunoichi differed from the training given to male ninjas, although they had a common core of skills, being trained in martial arts, such as taijutsu and ninjutsu. Kunoichi training tended to prioritize traditional female skills.
Etymology.
The term is thought to derive from the names of characters that resemble the three strokes in the Japanese kanji character for in the following stroke order:
The word "kunoichi" was not used frequently in the Edo period. This is probably because in this era, the kanji letter "女" was not written in regular script but usually in cursive script, and the cursive script of "女" cannot be decomposed into "く", "ノ", and "一".Yoshimaru
History of use.
The eighth volume of the ninja handbook "Bansenshukai" written in the late 17th century describes "Kunoichi-no-jutsu" (くノ一の術, Ninjutsu of female ninja). This can be translated as "a technique to use a female"Yoshimaru and was employed for infiltration purposes. The "Bansenshukai" compiles the knowledge of the clans in the regions of Iga and Kōga dedicated to the formation of ninjas. According to this document, the main function of the Kunoichi was espionage, finding functions in enemy house services, to gather knowledge, gain trust or listen to conversations. A disputed historical example is Mochizuki Chiyome, a 16th-century noble descendant who was commissioned by warlord Takeda Shingen to recruit women to create a secret network of hundreds of spies.
The meaning "female ninja" might be a purely modern use, that possibly first appeared in the novel "Ninpō Hakkenden" (忍法八犬伝) written by Futaro Yamada in 1964 and became popularized in the following years.Yoshimaru
Iga FC Kunoichi, a women's football club which is based in the city of Iga, takes its name from the term.