The system is summed up in its kata, or formal practice methods, and the specific techniques used to punch (vertical fist) and kick (snapping kicks). In many of the various forms of the system, sixteen kata (eight empty-hand, three bo, two sai a bo-bo kumite kata, a bo-sai kumite kata and one tuifa kata) are agreed upon as composing Isshin-ryu. These Kata include original developments of the Master, and inherited kata from the parent styles
Shimabuku Tatsuo (?????) (1908–1975) was born September 19, 1908 in Gushikawa village, Okinawa. Shimabuku began training under Shinko Ganeko (Ok. Ganiku), his maternal uncle. Ganeko later sent Shimabuku to study karate from Chotoku Kyan. He was age 18 at the time (1927). Chotoku Kyan would be his most influential instructor (and after whom he initially named his style Chan migwa Te, with Migwa being a reference to Chotoku Kyan's nickname stemming from his wearing of glasses and his small eyes). He also had lessons from Choki Motobu during the early 1940s in Naha, and, after Kyan's death, he continued to study karate privately with Chojun Miyagi at his home in Kyan village beginning in 1947. Shimabuku opened his first dojo in Konbu village and began teaching in late 1946 after being repatriated from Kyushu. He taught in Tairagawa village and also in Koza City before deciding to teach in his house in about 1948. On January 15, 1956, he held a meeting and announced that he was naming his new style of karate Isshin-ryu. Shimabuku's number one student, Eiko Kaneshi, was at the meeting and he asked Shimabuku, "Why such a funny name?" Tatsuo replied, "Because all things begin with one." At the age of 50 (c. 1959) Shimabuku began studying kobudo, the art of old traditional Okinawan weapons. The kobudo weapons included were the sai, bo, and tonfa, under Shinken Taira. He incorporated the kobudo that he had learned from Kyan and Taira into the Isshin-ryu system.