Kentsu Yabu was born on September 23, 1866 in Shuri, Okinawa. He was a prominent teacher of Shorin-ryu karate in Okinawa from the 1910s until the 1930s. Kentsu Yabu was among the first people to demonstrate karate in Hawaii.
In 1981 Kentsu Yabu joined the Japanese Army and served in Manchuria during the First Sino-Japanese War of 1894-1895. Kentsu Yabu was promoted to lieutenant, but to his students often refered to him as gunso, or sergeant.
After his service was over, Yabu studied at Shuri’s Prefectural Teacher’s Training College and in 1902 he became a teacher at Shuri’s Prefectural School Number One.
Kentsu Yabu visited the United States twice, once during 1921-1922 when his oldest son was having a baby, and again in 1927. During his second visit, Yabu returned to Okinawa through Hawaii and he ended up spending about nine months there. He spent most of his time on Oahu, but he also visited other islands. Kentsu Yabu gave two public demonstrations of karate at the Nuuanu YMCA in Honolulu.
In 1936, Yabu visited Tokyo and saw the young Shoshin Nagamine, who later became another well-known karate instructor.
Kentsu Yabu’s favorite kata reportedly included Gojushiho and Naihanchi.
Kentsu Yabu passed away at Shuri, Okinawa, on August 27, 1937.
As an instructor, Yabu’s teaching methods involved much more rote repetition than his predecessors. He was also credited with making Okinawan karate training more militaristic. As former military, he expected students to line up in rows and to respond by the numbers. This was probably also part of the general militarization of Japanese athletics common during the early 20th century.