Following the Second World War, martial arts in East Asia underwent various changes. This study focuses on the change from traditional martial arts to sports-oriented martial arts. It examines the emergence of karate as a sport during the Allied occupation of Japan. Kanbukan, founded in Japan by the Korean Kwaebyeong Yoon, was promoted as a sport version of karate that differed from traditional forms. Consequently, following the end of the war, Kanbukan introduced protective gear, held the first competition, created the first rules of the competition, published the first magazine, and formed the first international organization. “Sport Karate” is a detailed symbolic example of acculturation to a Western-centered culture in East Asian sports history. It is necessary to recall the legacy of Kanbukan and to reflect on the historical significance of Sport Karate, which facilitated the transition of traditional martial arts to sports.