Before modern times, the ninja worked secretly in the shadows, and a particularly shadowy figure is the female ninja or Kunoichi. While often portrayed as female spies, we're left with only hints and speculations about them. Based on passages from the "Bansenshukai," perhaps the most famous ninja manual, we investigate the history, mode of operation, and psychological tactics of the Kunoichi. Our search takes us to Tomi, a city in Nagano Prefecture where a mysterious female group once resided.