Kosen Judo is a variation of the Kodokan Judo. It’s rule set is derived from Kodokan judo, with emphasis on ne waza techniques. Koshen judo evolved and flourished in the beginning of the 20th century at koto senmon gakko technical colleges in Japan.This Judo style is emphasing ne waza more than typical Kodokan judo and is often regarded as separate martial art all together. In the latest years there is a lot of buzz around term “koshen judo” and all in thanks to Brazilian ju jitsu due to this two martial arts similarities.
Mentioned style of judo is one of two main approaches to judo training and competitions, in addition to Kodokan judo, in Japan and worldwide.
Kodokan judo in comparison to Koshen judo is by far the most dominant when we are talking about numbers of judokas, clubs and competitions around the globe. Kodokan competition rules are recognized globally by IJF (International Judo Federation) and are used on the Olympics and world championships. Koshen judo is is rarely seen outside of Japan, the country that spawned both styles. There are a few organisations that adopted and are using Koshen Judo to some degree, including European Sambo Federation, Freestyle Judo Alliance and International Brazilian Jiu Jitsu Foundation. Some of those organisations are allowing striking your opponent, some on the other hand put the emphases on the ne waza and or are closer to Kodokan rule set than others.
Differences between Koshen judo and Kodokan judo
The main difference in this two judo styles is simply put, the time-limits when performing Ne Waza and by that same token, the list of permitted techniques. In Kodokan Judo referee is obligated to stop “inactive” ne waza situations. This would be a situation where it looks like none of the two participants are in obvious advantage and there is no possibility of scoring in next 20 seconds. On the other side the Koshen judo has no time limitations for ne waza and rule set allows competitors to dedicate to the natural flow of the match weather it is taking place in ne waza or tachi waza (standing on the ground), also referee’s influence in match is somewhat smaller. In Kosheen judo referee’s role is to ensure competitors safety, signal when the match is over, weather that is by ippon or overall time limit is reached. Because of Kodokan Judo Ne Waza time-limits, certain techniques which work well in Kosen Judo become difficult or impossible to utilize in competitions, and certain others are banned completly.