Negishi-ryū (根岸流) is a Japanese tradition of shurikenjutsu, the art of throwing small steel spikes. It uses the bō-shuriken, a straight spike thrown so that it strikes point-first into its target. Its early history is only thinly recorded, but it is securely attested through its more recent transmitters.
The straight spike
The bō-shuriken is a plain bar of steel, thrown at distances that demand exact control of grip, release and rotation so that the point, rather than the side, meets the target. Negishi-ryū treats the throw as part of a whole posture and step rather than as an isolated flick of the hand, and the precision it asks for is considerable.
A thrown point rewards patience and exact distance far more than force.
A thinly recorded origin
The school is generally placed in the nineteenth century and linked to the Negishi family, but the founding details are not firmly established. Ryūpedia does not assert a precise founder or date where the surviving record does not support one, and the sources for shurikenjutsu in general are sparse.
The link to Meifu Shinkage-ryū
In the twentieth century Someya Chikatoshi, who had studied Negishi-ryū, drew on it to create Meifu Shinkage-ryū, a modern school of shurikenjutsu. Negishi-ryū is therefore the older parent of that better-known art, and the two are closely related.
Honesty note
Given how little is documented about its beginnings, strong or precise claims about the origin of Negishi-ryū should be treated with caution.