One historically accepted example of this is Mochizuki Chiyome, the 16th century wife of a Samurai warlord, who was tasked by her uncle with recruiting women to create an underground network of female espionage agents.
Chiyome recruited several young women who were recently orphaned, prostitutes or victims of the civil wars of the Sengoku period. She also recruited girls who were either lost or abandoned. Many people believed that she was helping these women, and giving them an opportunity to start up a new life. But in reality, they were trained to become highly efficient information gatherers and verifiers, seductresses, messengers and when necessary, assassins. The girls were taught all the skills of a miko (Shinto shrine maiden or a wandering female shaman), which allowed them to travel virtually anywhere without suspicion, receiving religious education to complete their disguise. Over time, Chiyome's kunoichi learned to effectively use more disguises such as actresses, prostitutes or geisha. This allowed them to move freely within villages, towns, castles and temples, and get closer to their targets. Eventually, Chiyome and her kunoichi had set up an extensive network of some 200-300 agents that served the Takeda clan and Shingen was always informed of all activities, putting him one step ahead of his opponents at all times until his mysterious death in 1573.
