Where did randori (a way of practicing judo) come from? It is generally believed that Jigoro Kano developed it, but is that true or not? Examination of both the origin and development of randori yielded the following results:

• One of the precursors to randori was kitoryu-midare, founded by Senai Ibaragi, who was active during the days of Iemitsu, the third Shogunate of the Tokugawa era. Senair Ibaragi placed a high value on agile motions in kitoryu-midare which he named tai, sha (throwing techniques), and uke.
• Randori evolved as practice methods changed. An example is nokori-ai, a method of practice in which uke attacks tori unless tori succeeds in throwing uke in kata-geiko. Seibei Suzuki, the fifth master of kitoryu at the end of the Tokugawa era, originally used the term randori, and randori became the common method in kobusho.
• Tenjin-shinyo-ryu, a style of jujitsu popular in the Edo era utilized randori as well as kitoryu. There were sixteen techniques including nage waza and shime waza in it. Because the uniform for practicing jujitsu had very short sleeves, techniques like seoi nage and harai goshi could be practiced, where tai otoshi could not be performed.
• Jigoro Kano, the founder of judo, lengthened the short sleeves of the jujitsu uniform with the idea of increased safety. This improvement enabled Jigoro Kano to widen and vary the number of offensive techniques. For example, more te-waza and ashi waza could be applied as there was more opportunity to off-balance an opponent with longer sleeves.
• With grappling techniques, Jigoro Kano invented a new method of practice in which the students started by facing each other on the ground.
• Jigoro Kano was not satisfied with randori in which students showed more strength than skill, and he insisted on randori with technique and agility.
• Thus, looking back at the development of randori from the Edo period up to today, the lengthening of the sleeves by Jigoro kano stands out as a major improvement. After that time, randori became a major influence in a revolution of technical development.