Itosu was instrumental in getting karate introduced into Okinawa's schools and served as a secretary to the last king of the Ryukyu Islands until Japan abolished the Okinawan monarchy. He also taught tote (tode/karate) at an Okinawan High School and in doing that he developed a more curriculum based approach for karate that remains in training today. He created the five Pinan kata as learning steps for students, because he felt the older forms (kata in Japanese) were too difficult for school children to learn. In theory, the five Pinan kata were derived from two older an more complex kata: kusanku and chiang nan.

As stated in an article karate historian by Charles Goodin in 2000, Kusanku is one of the most advanced of all kata in a number of styles and breaking it into 5 parts (and supplementing it with other kata) certainly did not make basic kata at all, and he goes on to argue they are too advanced for beginners (hence the probable selection by other major styles to not teach these at kyu rank levels). This is supported in Japan by numerous dojo who do not use the Pinan/Heian kata for kyu rank testing in the first first 3-5 years of dojo training. Often those styles (e.g. many Tani/Shukokai derived schools) use them as Dan rank testing kata (i.e. Pinan Shodan for a Shodan test through to Godan being demonstrated in a 5th Dan belt test i.e. Dan ranks matching the names of the kata). This matches the famous karate kata saying "san nen no kata", or 3 years one kata, which keeps students focused on more basic kata in the first few years to excel in core technique through focus (e.g. taikyoku variants in shito-ryu & gekisai in goju as 2 examples).

The Pinan kata have been transferred to many major styles and modified in that process. For example, as the Japanese FAJKO directory in 1919 states that, at the age of 51, Funakoshi sensei learned the Pinan Kata from Mabuni Kenwa and renamed and formatted them to be the Heian kata (for more details on this topic see: Karate technique selection & Street Fighting Statistics & Medical Outcomes by Armstrong et al., 2011). After this date and their modification they became key core belt test kata for Shotokan.

In 1908, he released the well known "Ten Precepts (Tode Jukun) of Karate," and in a similar vein, one of his instructors had earlier released similar precepts (Matsumura’s Karate precepts). Later, Funakkoshi, one of Itosu’s best known students released the famous 20 precepts document. Below is one translation of Itosu’s precepts:

Itosu's 10 precept's document:

Karate did not develop from Buddhism or Confucianism. In the past the Shorin-ryu school and the Shorei-ryu school were brought to Okinawa from China. Both of these schools have strong points, which I will now mention before there are too many changes:

1. Karate is not merely practiced for your own benefit; it can be used to protect one's family or master. It is not intended to be used against a single assailant but instead as a way of avoiding a fight should one be confronted by a villain or ruffian.

2. The purpose of karate is to make the muscles and bones hard as rock and to use the hands and legs as spears. If children were to begin training in Tang Te[1] while in elementary school, then they will be well suited for military service. Remember the words attributed to the Duke of Wellington after he defeated Napoleon: "The Battle of Waterloo was won on the playing fields of Eton."

3. Karate cannot be quickly learned. Like a slow moving bull, it eventually travels a thousand miles. If one trains diligently every day, then in three or four years one will come to understand karate. Those who train in this fashion will discover karate.

4. In karate, training of the hands and feet are important, so one must be thoroughly trained on the makiwara. In order to do this, drop your shoulders, open your lungs, take hold of your strength, grip the floor with your feet, and sink your energy into your lower abdomen. Practice using each arm one to two hundred times each day.

5. When one practices the stances of Tang Te, be sure to keep your back straight, lower your shoulders, put strength in your legs, stand firmly, and drop your energy into your lower abdomen.

6. Practice each of the techniques of karate repeatedly, the use of which is passed by word of mouth. Learn the explanations well, and decide when and in what manner to apply them when needed. Enter, counter, release is the rule of releasing hand (torite).

7. You must decide if karate is for your health or to aid your duty.

8. When you train, do so as if on the battlefield. Your eyes should glare, shoulders drop, and body harden. You should always train with intensity and spirit, and in this way you will naturally be ready.

9. One must not overtrain; this will cause you to lose the energy in your lower abdomen and will be harmful to your body. Your face and eyes will turn red. Train wisely.

10. In the past, masters of karate have enjoyed long lives. Karate aids in developing the bones and muscles. It helps the digestion as well as the circulation. If karate should be introduced beginning in the elementary schools, then we will produce many men each capable of defeating ten assailants.

I further believe this can be done by having all students at the Okinawa Teachers' College practice karate. In this way, after graduation, they can teach at the elementary schools at which they have been taught. I believe this will be a great benefit to our nation and our military. It is my hope you will seriously consider my suggestion.