Shinkichi Shimabuku was born in Chun Village, Okinawa, on September 19, 1906. He was one of ten children born into a farming family. By the age of eight, he had a strong desire to study the martial arts. He walked several miles to the home of his uncle, Urshu Matsumura (Kamasu Chan), who was a Shuri-te instructor, only to be turned away.
This did not discourage young Shimabuku, however, as he made the trek every day until his uncle relented and accepted him as a student. At first, Matsumura would only give him menial chores to perform around the dojo, but after a few weeks he saw his nephews true desire to learn and began his training.
He studied informally with his uncle for several years. By the time Shimabuku was a teenager, he had attained the physical level of a person six years his senior. His physical condition was due to his karate training as well as his working on the family farm. He excelled in athletic events on the island. By the time he was seventeen, he was constantly winning in two of his favorite events, the javelin throw and the high jump.
Around the age of twenty-three, Shimabuku desired to further his knowledge and began to study under the legendary Shuri-te (Shorin-Ryu) master, Chotoku Kyan in the village of Kadena. He began his training with Master Kyan in 1929 while attending the Okinawa Prefectural Agricultural School. Within a short time, he became Master Kyan’s best student and, under Kyan’s instruction, learned the katas: Seisan, Naihanchin, Wansu, Kusanku, and Tokumine-no-kin-bo. He also began his study of ‘Ki’ for which Master Kyan was most noted. Shimabuku studied with Master Kyan until Kyan’s death in 1945. He always considered Master Kyan his first formal sensei and was very loyal to him.
While continuing his studies with Master Kyan, Shimabuku sought out another famous Shorin-Ryu instructor, Master Choki Motobu, during the early 1930’s. Master Motobu was known throughout the island for his fighting prowess, and as his student, Shimabuku quickly developed his fighting skills into a precise art.
Shimabuku had always been fascinated by Naha-te (Goju-Ryu) and sought out Master Chojun Miyagi, the founder of Goju-Ryu, after Master Kyan’s death. Enrolling in his dojo, Shimabuku quickly became Master Miyagi’s best student, and from him learned the Seiuchin kata and the all- important Sanchin kata. Shimabuku studied with Master Miyagi until Miyagi’s death in 1953.
After his apprenticeship under these three masters, Shimabuku entered a special martial arts festival on Okinawa during the mid 1930’s. His performance of both Shorin-Ryu and Goju-Ryu katas so impressed the spectators, that by 1940, he was recognized throughout the Ryukyu Islands as the foremost proponent of Shorin-Ryu and Goju-Ryu karate. He was the first person ever to master both systems.
Coming from a farming family, Master Shimabuku had always been poor, yet he was very innovative and opportunistic. He had a natural talent in adapting things to work for him. As a young man, he discovered a way to bind tile to the roofs of the homes in Chun Village without using mud, which had been the traditional way. Prior to World War II, he saw an opportunity and started a small business. Purchasing several horses and carts, he received a contract to help in the construction of Japanese air fields in Kadena. He was doing quite well until the allied invasion of Okinawa began. During one of the bombing raids by allied forces, his business was destroyed.
During World War II, Master Shimabuku’s reputation as an expert in karate was such that Japanese officers stationed on Okinawa kept him from military conscription in exchange for karate lessons. After the war, he resumed farming and taught karate to a handful of students. However, due to his reputation it was only a short time before U.S. military personnel began to seek him out for instruction. Once at a demonstration, he missed the nail that he was driving into a board with his Shuto hand and cut the back of his hand. He put a handful of dirt on the cut and finished the demonstration.
Master Shimabuku continued to study and develop his skills in both styles, but he was not satified that either style was the ultimate fighting art. His interest in acnient weapons (Kobudo) continued to grow and he sought out the best weapons instructors on the island. His first weapons instructor was Master Moden Yabiku. In a short time, he mastered such weapons as the Bo and the Sai. During the late 1950's and early 1960's, he continued his study of Kobudo with Master Yabiku's top student, Shinken Taira. This training took place in Master Shimabuku's dojo in Agena.
It was during the late 1940’s that Master Shimabuku began experimenting with different basic techniques and kata from both the Shorin-Ryu and Goju-Ryu systems as well as Kobudo. He also experimented with many of his own ideas. He called this style Chan migwha-te which means ‘small-eyed Kyan’s karate’. Master Kyan’s nickname was ‘migwha’, meaning ‘small-eyed’, and ‘Chan’ is the Okinawan pronunciation of Kyan. Chan migwha-te was the style taught to U.S. military personnel in the late 1940’s and early 1950’s.
By the early 1950’s Master Shimabuku was refining his karate teachings combining what he felt was the best of the Shorin-Ryu and Goju-Ryu styles, and incorporating his own techniques. While his experimentation continued, his adaptation of techniques and kata were not widely publicized. He consulted with several of the masters on Okinawa concerning his wish to develop a new style. Because he was highly respected as a karate master, he received their blessing. (This would later be rescinded due to the many radical changes made in traditional Okinawan karate.)
One night in 1954, Master Shimabuku fell asleep and dreamed of a beautiful sea goddess, half woman, half serpent, named ‘Mizu-Gami’. She represented the calmness a martial artist should display in facing turbulent conditions, symbolized by the churning sea, but having the strength of the serpent, if needed. Her left hand was open as a sign of peace, but her right hand was clenched in a fist indicating her willingness to fight if the need arose.
A dragon appeared in the sky symbolizing the fighting fury displayed by a dragon as does the half-serpent body of Mizu-Gami. The ascending dragon also represents good luck. Three stars appeared symbolizing the birth of a new system of karate. The left star represented Shorin-Ryu (the mother), the right star represented Goju-Ryu (the father), and the middle star representing Isshin-Ryu (the child). The gray evening sky symbolized serenity and implies that karate is to be used only for self-defense.
Master Shimabuku also said that the three stars denoted that it was dark or nightfall. The dragon in his dream was a good luck symbol in Okinawan folk lore. It symbolizes the dragon palace that was located at the bottom of the ocean.
The next morning when Master Shimabuku awoke, he felt that his dream had been a divine revelation. He met with his top student, Eiko Kaneshi, and told him of his dream and his desire to break away from Okinawan tradition and start a new style of karate. The date was January 15, 1954. Upon announcing his decision to start a new style, many of his Okinawan students left, including his brother Eizo.
The new system was not initially given a name, and in fact, went through two name modifications before Isshin-Ryu was finally adopted. However, the official birth of Isshin-Ryu karate is January 15, 1954. The Mizu Gami was drawn from Master Shimabuku’s description by Shosu Nakamine, Kaneshi’s uncle, and was chosen to be the symbol for Isshin-Ryu karate.
During his karate career, Master Shimabuku changed his name to "Tatsuo," meaning ‘dragon boy.' Whenever ask about this change, Master Shimabuku would reply that "Tatsuo" was his chosen karate name. He was also given the nickname, ‘Sunsu’, meaning ‘strong man’. It has been speculated that ‘Sunsu’ was given to him due to his abnormal strength developed through the practice of the ‘Sanchin’ kata. Master Shimabuku was only around five feet tall and weighed approximately one hundred and twenty pounds, yet he possessed unusual strength for a man his size.