Chojun Miyagi Sensei (April 25, 1888—October 8, 1953) was born in Naha, Okinawa and was adopted son of a wealthy businessman. Miyagi began his study in Budo at the age of 12. He first learned martial arts from Ryuko Aragaki in 1900. Ryuko Sensei introduced the young Miyagi to the rudiments and fundamentals of Budo. Ryuko Sensei specialized in Junbi undo, Hojo undo, kihon waza, etc. After a two year training period (this was when Miyagi Sensei's training peaked with Ryuko Sensei). Ryuko Arakaki Sensei introduced him to Kanryo Higaonna Sensei. Under the tutelage of this Master, Miyagi underwent a very long and arduous period of training learning the complex system of Naha-te. Please stay tuned for the story of how Miyagi Sensei met Ryuko Sensei at a young age of 12.
After the death of Master Kanryo Higashionna, Miyagi travelled to Fukien Province in China as his teacher had done before him. In China he studied the Shaolin and Pa Kua forms of Chinese boxing. From the blending of these systems, the hard linear/external form of Shaolin, the soft circular/internal form of Pa Kua, and his native Naha-Te, a new system emerged. However, it was not until 1929 that Chojun Miyagi named the system Goju-ryu, meaning hard-soft style.
After some years in China, Chojun Miyagi returned to Naha where he opened a dojo (training hall). He taught for many years, and even though Miyagi's reputation as a karate man was enormous, and even Kano Jigoro Sensei, the founder of judo, came to Okinawa to learn specific karate takedowns, his greatest achievements lie in popularization and the organization of karate teaching methods.
He introduced karate into Okinawa police work, high schools and other fields of society. He revised and further developed Kata Sanchin - the hard aspect of Goju, and created Kata Tensho - the soft aspect. These kata are considered to contain the essence of the Goju-ryu style while Suparinpe is a highest and full syllabus Goju-ryu kata and Shisochin was Miyagi's favourite kata at the end of his years. Tensho was influenced by the White Crane kata Rokkishu (six internal power hands), which he learned from his long-time friend and mentor Master Gokenki. With a goal of unification of various karate styles which was in fashion at that time, he also created more Shuri te-like katas Gekisai Ichi and Gekisai Ni in 1940, taking techniques from higher forms (notably Suparimpe also upper block was uncommon for Goju-ryu at that time) and incorporating them into a shorter forms. It is said he created these kata to bridge the gap between Sanchin Kata and Saifa Kata, which contains much more complex moves compared to Sanchin kata. In a side note, Matsubayashi-ryu practice beginner forms also based on the Geki-sai series.
Chojun Miyagi Sensei was a man of extremely mild temperament and it is said that he was a very humble man. He lived according to the principles of martial arts, that of non-violence. Master Miyagi died in Okinawa on October 8, 1953 from a heart-attack (most common reason, but others have said otherwise).
Some of his more notable students were Jinan Shinzato (died in the Battle of Okinawa 1945), Seiko Higa (also a student of Kanryo Higaonna), Seikichi Toguchi (founder of the Shorei-Kan dojo), Ei'ichi Miyazato (founder of the Jundokan dojo), Meitoku Yagi (founder of the Meibukan dojo, he eventually accepted late master Miyagi's gi and obi from Miyagi's family and become the rightful heir to the system), and in Japan, Gogen Yamaguchi (founder of Goju-kai and who, after short training with Miyagi, spent later most of his time studying katas under Meitoku Yagi while being himself a representative of Goju-ryu in Japan).
This rare pic of Miyagi Sensei at the far right shows the vigour's of tradition Sanchin training.
As a nice side note, the movie series, "The Karate Kid", uses the reference to Chojun Miyagi Sensei for Pat Morita's character, "Mr. Miyagi".