Rules of the Dojo by Kyuzo Mifune, 10th dan

To master an actual technique, mental culture should come first. Acquiring a technique requires a careful, modest, non-mean, free and attentive mind.
In other words a player should do his utmost and nothing less. …..Kyuzo Mifune

Have no falsehood in mind.

Ruluctance or deceit are not conducive to the inner harmony required by Judo practice.

Do not lose self-confidence.

Learn to act wholeheartedly, without hesitation. Show reverance toward the practice of Judo, by keeping your mind in it.

Keep your balance.

The center of gravity follows the movement of the body. The center of gravity is the most important element in maintaining stablility. If it is lost, the body is naturally unbalanced. Thus, fix your mind so that your body is always in balance.

Utilize your strength efficiently.

Minimize the use of strength with the quickest movement of body. Acknowledge that what is called stillness and motion is nothing but an endlessly repeated process.

Don’t discontinue training.

Mastery of Judo cannot be accomplished in a short time. Since skills depend on mental and physical application, constant training is essential.