Medieval weaponry was blunt, sharp, and quite painful. The kaginawa (rope and hook) was used during the Sengoku period of Japan by samurai and shinobi alike.
While the roles shinobi played in this medieval society were numerous (i.e. kinju bodyguards, intelligence agents, scouts, etc.) in some capacity shinobi functioned as bounty hunters, using the kaginawa to restrain flighty criminals. If necessary, the kaginawa was also used to climb, pull down barricades, lock doors, cross rivers, and, of course, as a ship anchor.
Using the Kaginawa in Combat
According to the 20th century ninjutsu researcher Gingetsu Itoh, one method of protection used by the shinobi dubbed ‘Shun Kan Sa-Yo’, uses a principle of taking an opponent’s attention or breaking the opponent’s focus.
In elaborating on the applications of the principle, Itoh explains that it works by taking advantage of an inborn reflex to “wince” or “blink”. During this brief interval, the shinobi, whose actions induced such reflexes, makes a quick escape as if to disappear from the eyes of the bewildered opponent.
But fleeing is not the only option. One can envision how this principle of stimulating the flinch response in an opponent could reveal a gap in his defense.
I chose to experiment with this principle along with the equipment that the historical shinobi was known to carry- the kaginawa (hook and rope), sword, and an amigasa (wide-brimmed hat, though I opted for a modern ballcap because traditional amigasa are not readily available.
In the video below, you will observe the principle of ‘Shun Kan Sa-Yo’ in application, along with other ninjutsu related material. Imagine a time (15th-17th cent.) when hooks were sunk into flesh to bar escape:
Examining the “Ki-Ai” – Excerpt from Ninjutsu: A Commoner’s Guide
“Itoh writes that one should scream “like a lion”, offering opening for speculation that the shinobi may not only have found utility in using the kiai, but scientific observations holding true, Itoh’s description of Shun Ka SaYo further substantiates the idea that the ninja were men of war who had seen real human behavior under conflict and took note of what behaviors could be taken advantage of. How so?
A highly elucidative book that examines the psychological ramifications of combat and killing must be called in for support: On Killing by Lt. Col. Dave Grossman.
Grossman, explains that intra-species aggression, such as that which is displayed in warfare has been observed to confound the fight-or-flight paradigm of human responses to psychological stress.
Unlike with inter-species aggression (against non-humans) wherein the responses evince this paradigm, intra-species aggression adds to the fight-or-flight scheme to “include posturing and submission”.16
Posturing is a common technique utilized by many species in response to intra-species threats to suggest dominance and power. Seldom ever does the posturing in these situations boil over into an all-out fight to the death with a member of the same species. And in this regard, the phenomenon may be thought of as an evolutionarily adaptive attempt to preserve a social hierarchy wherein everyone is dependent on one another to some degree. Rather than kill a useful member of one’s own species, animals in an intra-species conflict tend to submit or flee from the more dominant animal and retain a lower social status, and indeed, this phenomenon is even observable to a degree in humans.
As related by Rory Miller in his publication Meditations on Violence, human beings engage in a form interspecies aggression that functions in the determination of social status. Referred to as “the Monkey Dance”, Miller explains that posturing is a component of the display of dominance that can break down into aggressive behavior that does not typically result in death. In such situations, if one’s posture/presence is good enough, a challenge to status can be avoided altogether. So what does this have to do with a kiai?
Regarding these insights into animal and human psychology, a kiai may be thought of as a component to effective human posturing in the event that inter-species aggression is potentiated.”