In 1947, the ban on martial arts practice was lifted by the American occupation troops. In 1949, karateka who reassembled after the war organized the beginnings of the Japan Karate Association (JKA) to honor Master Funakoshi. The JKA was formally established in 1955 with Master Funakoshi as Chief Instructor Emeritus and Master Nakayama as Chief Instructor. The JKA was chartered as a corporation by the Japanese Ministry of Education in 1958. The JKA was the first karate organization to be recognized and chartered by a government organization.

As a chartered corporation of the Japanese Ministry of Education, the JKA's activities and programs are under the jurisdiction of this government agency. For example, the Instructors Training Program, as a formal educational program, is certified by the Japanese Ministry of Education. The JKA is one of the two largest karate organizations in the world (the other being the International Tae Kwon Do Federation).

The International Shotokan Karate Federation (ISKF), affiliated with the JKA, was established in 1977. The ISKF coordinates efforts to bring JKA programs and develop JKA organizations throughout North, Central, and South America, and the Caribbean. The ISKF also administers the JKA Instructor Training Program within its geographical region.

Master Teruyuki Okazaki, 9th degree black belt, is the Chief Instructor and Chairman of the ISKF. Master Okazaki was the right-hand man to Master Nakayama in the early days of establishing the JKA. He also played a crucial role in establishing and developing JKA tournament rules and the JKA Instructors Training Program.

The JKA of Colorado was established in 1974 with Sensei Yaguchi, 8th degree black belt, as Chief Instructor and Chairman. The JKA of Colorado is also the headquarters for the Mountain States Region of the ISKF. The Mountain States Region is the youngest region in the U.S. but, under the guidance of Sensei Yaguchi, has developed numerous international and national-level competitors. The JKA of Colorado is one of the only organizations sanctioned to offer the JKA Instructors Training Program in North, Central, and South America.