Koppōjutsu (骨法術) [bone method] is a system of close combat that focuses on breaking posture and setting up opponents for breaking bones and joints. 

The techniques of koppōjutsu are direct and compact. It uses a great deal of misdirection and multiple attack angles to disorient the opponent and strike from unexpected directions. 

Koppōjutsu kamae are fairly shallow and wide. A critical aspect of koppōjutsu is a technique called sokushin sokuhō, which is a cross-step. This is reflected in the kamae, which are taken at angles allowing the ability to cross-step easily, while being able to kick or strike. 

The waza of koppōjutsu are explosive and follow a shortest straight line path. These include strikes, kicks, throws, locks and chokes. 

Koppōjutsu jutsu follow a principle of misdirection. Each strike or attack is done in such a way that it is hidden. This unbalances the opponent and opens up another hidden attack from a different angle. In koppōjutsu, the opponent should never be able to tell where the attack is coming from.

Koppōjutsu kata focus on surprise to flow around the opponents attacks and strike from a blind angle or an unexpected direction. The attacks are direct and set up the opponent's posture to be broken.