top of page

History and Philosophy



Jikan Dojo Goshin Jutsu was initially developed by Jikan Dojo Chief Instructor Jacob Greasley to preserve his knowledge and experiences in self-defence and martial arts that fell outside of his primary martial arts curricula of traditional karate and jujutsu. The system was later expanded to include simplified self-defence methods extracted from Japanese karate and jujutsu curriculums.


As a teenager and later in his early 20s sensei Jacob trained in a variety of martial arts. He achieved junior ranks in Judo and Taekwondo while growing up in the Caribbean and later during his military postings in the UK had prolonged training stints in Bujinkan Taijutsu and Israeli Krav Maga. During several years in the British Army he came to a new appreciation of military conflict. While on a tour of duty in Afghanistan he learnt a few techniques that were practiced in the United States Marine Corp Martial Arts Program (MCMAP), not greatly different from the martial arts techniques he previously studied but with a different level of intensity and realism. After leaving the armed forces he became involved in private security work as a bouncer around England and Wales experiencing a variety of violent confrontations. of Japan.


In Japanese karate he began to search deeper for the old-school karate methods and the applications of karate kata that had been greatly neglected by modern sport karate organisations. His exploration of karate kata led to a discovery of a whole new world of fascinating self-defence techniques and principles.


In his years of teaching he observed that many beginners in martial arts classes were put off by the length of time required to develop proficiency in traditional martial arts to be effective in self-defence. For this reason he worked tirelessly to create effective and realistic self-defence courses based on his own experiences and well-documented research and statistics. He studied medical reports that were compiled from various A&E departments that dealt with injuries from street violence. He also looked at trends in statistics from police forces in the USA, UK and Australia about violent crimes. He even studied research on the psychology of violence by prominent psychologists and criminologists.


With the knowledge gathered he devised a system which employs proven traditional martial arts techniques that were simple enough to allow novices to deal with the most common attacks in the modern world. The Level 1 course equates to Yellow Belt in Jikan Dojo Goshin Jutsu and covers effective defences against 10 common attacks. It also teaches use of the body’s ‘natural weapons’ that don’t require years of training to be effective. In addition to the techniques, the Level 1 course covers principles of self-defence that make the techniques more likely to succeed and to increase a practitioner’s chances of survivability.


The Level 2 course equates to Orange Belt and goes on to more advanced self-defence scenarios that were beyond the scope of the Level 1 course. This includes defence against weapon attacks. After Orange belt the program expands beyond the set trained-responses previously taught to equip practitioners with further tools for self-defence application. Intensity and realism are essential aspects of the program. Jikan Dojo Goshin Jutsu may also serve to bridge a gap between karate and jujutsu practice as it contains elements of both martial arts.


A dan grade in Jikan Dojo Goshin Jutsu would be able to comfortably participate in training in a variety of other Japanese martial arts. Currently Jikan Dojo Goshin Jutsu is accredited by Seiken Shudo Kai, the Japanese Budo Organisation lead by sensei Jacob’s personal instructor Master Sei Iwasa of Japan.

bottom of page