What is the Kusarigama—From Agricultural Tool to Weapon

The kusarigama is a composite weapon consisting of a sickle (kama) with a chain (kusari) attached to its handle, with a weight (fundou) or iron ball tied to the end. It is an agricultural sickle adapted and modified as a weapon, and although it represents an entirely different lineage of weapons from swords, it is frequently discussed in the context of confrontations with the katana in the history of Japanese martial arts.

While the origins of the kusarigama are not entirely clear, it is said to have been systematized as a martial art from the late Muromachi period through the Sengoku period. The prevailing theory is that it originated as an agricultural tool or everyday implement repurposed and modified as a weapon during a time when peasants and ninja (ninjutsu practitioners) could not legally possess formal swords. Today, various lineages such as "kusarigama-jutsu" and "fundou-kusarigama-jutsu" continue to be transmitted, and their practical utility and distinctive aesthetics are carried forward to the present day.

The structure of the kusarigama comprises three main parts. First, the "kama (sickle) section" is the bladed portion that performs actual cutting and piercing, and like a genuine katana, it is forged from steel. Second, the "hilt section" (tsuka) is made of wood or metal and not only secures the sickle blade but also maintains the balance of the entire weapon. Third, the "chain (kusari) and weight section" functions for both attack and defense, allowing the weapon to reach distances beyond what the sickle alone could achieve.

The Tactical Relationship Between Kusarigama and Katana—As a Weapon Against the Sword

The primary reason the kusarigama occupies such a unique position in Japanese martial history is that it developed as a weapon specifically designed to counter the katana. When facing a katana head-on, it is difficult for a sickle of agricultural origin to even enter the sword's effective range. The tactic that was therefore conceived was to ensnare the katana with a weighted chain, neutralize the opponent's weapon, and then finish with the sickle.

This tactic of "binding the katana with the chain and cutting with the sickle" requires extremely sophisticated technique. It demands simultaneous mastery of the technical skill to throw the chain with appropriate force to wrap around the blade or hilt, the physical ability to quickly close distance the moment it makes contact, and the judgment to accurately target vital points with the sickle. For this reason, training in kusarigama-jutsu is said to require as many years or more than training in katana technique.

The most famous historical encounter between kusarigama and katana is the legendary duel between Miyamoto Musashi and Shishido Baiken, a master of kusarigama-jutsu. While this story is recorded in texts such as the "Nitenki," much remains unclear about whether it is historically factual. Nevertheless, the anecdote that the swordmaster Musashi struggled in his confrontation with such a specialized weapon suggests that the kusarigama genuinely possessed high effectiveness as a weapon against the katana.

Schools and Technical Systems—The Diversity of Kusarigama-Jutsu

Schools of kusarigama-jutsu are distributed throughout Japan, each with their own distinctive technical systems. Major schools include "Shinten-ryu," "kusarigama-jutsu branches of Shinkage-ryu," and "kusarigama techniques of Hozoin-ryu." Moreover, each school varies subtly in chain length, weight of the fundou, and sickle shape, with each school's tactical philosophy reflected in the design of their weapons.

Chain length typically ranges from 1 to 3 meters, with shorter chains suited for quick ensnaring and longer chains for controlling at greater distances. The weight of the fundou also varies by school; heavier weights allow for powerful strikes utilizing momentum but are cumbersome to handle, while lighter weights enable more agile movements but sacrifice striking power. These differences in weapon design give rise to the distinctive techniques of each school.

Ninja and Kusarigama—Between Reality and Exaggeration

In modern times, the kusarigama is strongly associated with the image of a "ninja weapon" and frequently appears in films, anime, and games. However, from a historical perspective, there is little evidence that the kusarigama was the exclusive weapon of ninja. While it is true that ninja (ninjutsu practitioners) were skilled craftspeople who adapted various tools and weapons according to circumstances, it is historically inaccurate to limit the kusarigama to a specific group of practitioners.

Rather, the kusarigama is thought to have become popular as a weapon used for self-defense among those who could not constantly carry a katana—such as peasants, minor samurai, and wandering martial artists. During the Edo period, when swords were expensive and non-samurai were subject to various restrictions on carrying weapons, the kusarigama, repurposed from agricultural tools, was a more accessible tool for self-defense and martial practice.

The Modern Position of the Kusarigama

In modern Japan, the kusarigama is subject to regulation under the Swords and Firearms Prohibition Law as a "composite weapon combining a blade and chain." If the blade is 5.5 centimeters or longer, it may be considered a "dangerous weapon" under this law. For this reason, wooden or resin safety versions are commonly used for martial arts practice.

From the perspective of martial arts and combat sports, kusarigama-jutsu continues to be transmitted today as a form of Japanese traditional martial arts (koryū) by classical martial arts groups throughout the country. Among the schools recognized by the Classical Martial Arts Promotion Society under the All Japan Kendo Association, there are schools that include kusarigama-jutsu, and their techniques are passed on to the next generation through demonstrations at exhibition competitions.

While the katana embodies the essence of refined beauty as the "soul of the samurai," the kusarigama exemplifies the diversity and ingenuity of Japanese weapon culture by rising from humble origins as an agricultural or common tool to become a sophisticated martial art. The dynamic of confrontation between the two provides an indispensable contrast in describing the richness of Japanese sword culture and martial history.