The gatekeeper's problem
Masaki-ryū (正木流) is a school of Japanese weapon arts founded in the eighteenth century by Masaki Toshimitsu (正木俊光, 1689–1776), a retainer of the Ōgaki domain in Mino province. Toshimitsu is best remembered for the manriki-gusari (万力鎖), a short chain weighted at both ends. Masaki-ryū tradition places him on guard duty at Edo Castle's Ōtemon, the main entrance used by daimyō and official processions. Historical research on Edo Castle gatekeeping shows that such posts did more than defend the walls: guards controlled movement and night passage, upheld ritual, and maintained samurai order at the boundary between castle and city.
Within that setting, the school's founding account presents the manriki-gusari as an answer to a practical problem. A guard needed to stop and restrain trouble quickly without drawing a sword or leaving bloodshed at the castle entrance. When the person involved was a samurai of rank, a nonlethal response also reduced the risk of turning an incident of public order into a political dispute. The compact chain could entangle, strike and restrain at close quarters while avoiding the legal and social consequences attached to drawing a sword.
To stop an attacker without shedding blood: the weighted chain as a weapon of protection rather than execution.
A synthesis of many teachers
Toshimitsu's own transmission documents, in which he signs himself Masaki Tarōdayū Toshimitsu, record a long apprenticeship across several traditions of Japan: sword training in the Kotōda line of Ittō-ryū, naginata under teachers of the Sen'i-ryū, and further study in spear methods and throwing techniques. Those were parts of the founder's personal training history, not a list of the Masaki-ryū curriculum. The transmitted school centres on the manriki-gusari, with kusarigama taught to senior practitioners; it does not contain naginatajutsu. Toshimitsu died in 1776 at the age of eighty-eight and was buried in Ōgaki.
A school of self-protection
The gate story is only one expression of the school's purpose. Masaki-kai teaching describes Masaki-ryū as goshin no ryūha, a school of self-protection. Its compact weapon made sense not only at a castle gate but also in the close quarters of an Edo-period city, where immediately resorting to the sword could be legally, socially and politically dangerous. This framing explains why restraint is central to the school's identity: the aim is effective protection without treating every confrontation as a killing encounter.
The school after its founder
The Masaki tradition remained rooted in Ōgaki through the Edo period and was carried into the modern era through successive teachers. Masaki-kai in Tokyo continues to transmit Masaki-ryū manriki-gusari alongside Edo machikata jutte and arresting-cord methods. In 1998 Nawa Yumio abolished the sōke system and established a shihanke system, which continues today. Masaki-kai is not currently a member of the Nihon Kobudō Kyōkai. The association's present roster does contain a separate combined listing for Suiō-ryū iai kenpō and Masaki-ryū kusarigamajutsu, but that listing is not evidence of Masaki-kai membership.