The Kodokan was first established in 1882 with only nine students the first year. Soon, the new Kodokan Judo became the center of public attention. But its’ practical merits were looked upon with contempt by most old jujitsu men, including master Hikosuke Totsuka. There soon developed a keen rivalry between the Kodokan and the Totsuka School. Things came to a head in 1886. In Kano's words: "Under the auspices of the Chief of Metropolitan Police, a grand tournament was arranged between both schools. This was a decisive battle. Defeat would have been fatal to the Kodokan. But in that tournament, to which each school sent 15 picked men, the Kodokan won all the bouts excepting two, which ended in a draw. That brilliant victory established once and for all the supremacy of Kodokan Judo over all jujitsu schools."

One of the principles of judo is that a stronger opponent can be defeated by turning his strength against himself. Professor Kano explains how in yielding there is strength: "Suppose we estimate the strength of a man in units of one. Let us say that the strength of this man is 10 units, whereas my strength, less than his, is 7 units. Then if he pushes me with all his force, I shall certainly be pushed back or thrown down, even if I use all my strength against him. This would happen from opposing strength to strength. But if instead of opposing him, I leave him unresisted, withdrawing my body just as much as he pushes, at the same time keeping my balance, he will naturally lean forward and lose his balance. In this new position, he may become weak (not in actual physical strength, but because of his awkward position) as to reduce his strength for the moment, say to 3 units only instead of 10 units. But meanwhile I, by keeping my balance, retain my full strength, as originally represented by 7 units. Here then, I am momentarily in a superior position, and I can defeat my opponent by using only half of my strength, or 3 1/2 units against his 3 units. This leaves one-half of my strength available for any other purpose. If I had greater strength than my opponent, I could of course push him back. But even if I wished to and had the power to do so, it would still be better for me first to give way, because by so doing, I should have greatly saved my energy and exhausted my opponent's."
Jigoro Kano died in May 1938 while returning from the Cairo International Olympic Conference. Men's judo was first included in the Olympic Games in 1964 and became a permanent part of the Games in 1972. In 1992, women's judo became part of the Olympic Games as well. Kano defined the two principles of Kodokan Judo as "Maximum Efficiency with Minimum Effort" and "Mutual Welfare and Benefit". He said that "physical education should train the body to be strong, healthy and useful in actual life and also make a contribution to the culture of the mind." His system of judo is just that.