Within Bujinkan ninjutsu there is the concept of henka (variation). To take the basic kata and vary some aspect of it, whether it be striking somewhere different, move outside a line of attack instead of inside, hit with a different striking form, or lock and restrain instead of strike. You vary one thing, then vary another until you are doing a different technique but in the same manner or feeling as the original. The idea is to build from a solid foundation of the being able to demonstrate the core kata, being able to do it with nagare (fluidity / flow) and then develop henka.

This can be a difficult concept for the beginner to grasp, and there are times where you show a technique, the student performs it but incorrectly in some way and claims this is a henka. This is a misguided application of the concept of henka, as the ability to do the kata must be learned before varying it. However the benefit of this method of teaching is the student learns a principle rather than a rigid technique, the principle of interrupting action and balance, the principle of causing the aggressor to overextend, the principle of spinal manipulation etc.

At the core of Bujinkan ninjutsu are the eight kata of the kihon happo (fundamental eight) and the five of the san shin no kata (three spirit kata). From these building blocks comes Bujinkan taijutsu (unarmed techniques). Another unique principle of this art is the idea that the body dynamics used in the taijutsu are the same with weapons, with adjustments made for weapon length, and unique features of the weapon.

This enables the student to learn weapons along with taijutsu, and builds their abilities in a parallel fashion. By using this mixed approach of taijutsu, weapons, and variation in the training it helps the student not get fixed into a rigid form, or to feel constrained to a certain response to a certain attack.

The punch does not always need to be blocked, nor evaded, nor absorbed. It has to be appropriate to the unique situation that is happening right then, and be at an appropriate level of response to the threat. It’s not appropriate to render a drunken friend unconscious if he/she is just mucking about, but it may be if the assailant has deadly intention. This is then developed into not trying to achieve a technique if it’s not appropriate.

To try and throw someone who has regained their balance, or strike someone who has retreated out of range results in the student over-extending themselves, and creating vulnerabilities. So students try to develop a flexible and adaptive spirit to conflict.

This approach to training doesn’t work for everyone as some people work best within set boundaries and set timetables. But this is normal as everyone has their own style of learning and assimilating information and skills. Those that do find this approach to training suitable, also find there are many ways to counter attacks. This in turn helps them develop a flexible approach to dealing with confrontation so they don’t have to use physical intervention as there first choice of response.

This leads to one other principle in ninjutsu that is quite different from competitive forms of martial art – one of evasion. The original practitioners of ninjutsu didn’t want to fight or even be noticed, so they did everything they could to avoid attention and confrontation, even if they appeared to others to be cowardly or dishonourable.

Today this translates and has evolved to avoiding confrontation by body language skills, negotiating skills and evasion skills. If someone wants to fight don’t give them what they want, unless you really have no other choice. There will of course be situations where you don’t have the opportunity to go unnoticed, to negotiate, or to evade a confrontation; this is where appropriate application of taijutsu comes into play.

The skills learned in taijutsu gives the Bujinkan student the ability to control and end a physical confrontation in as short a time as possible – even if it’s only to get the assailant out of the way to make good an escape.