Born in 1923, Masutatsu Oyama began studying kenpo at the age of nine and had attained the first level of proficiency (shodan) by his second year in middle school.

In 1928, he began studying at a karate dojo, which was headed by Gichin Funakoshi who introduced Karate into Japan from Okinawa. At the age of seventeen, Oyama had attained his second dan. Then In 1941, he matriculated into Takushoku University and, in 1943, began studying with Sodeiju, a leading figure in the karate world of the time. By the age of twenty, he was fourth dan.

In 1945, he volunteered for service in the Japanese army and was sent south, where the fighting was taking place. After World War 2 had come to an end soon thereafter, he isolated himself in a temple on Mt. Minobu and trained in karate for a full year. In 1947, Having taken first place in the initial post-war All-Japan Championship Tournament, he decided to devote the rest of his life exclusively to this martial art.

In 1948, he constructed a rude hut for himself on Mt. Kiyozumi, in Chiba Prefecture, and once again trained strenuously, this time for one year and eight months, during which he fed himself on grasses and berries. After coming down from the mountain in 1949, in order to train in breaking horns from bulls, he took upÊresidence not far from a slaughter yard. During his stay there, he broke the horns of fifty bulls.

In 1952, together with Kokichi Endo, an out-standing judo expert, he travel to the United States, where he gave 270 exhibition matches and appeared on television seven times. Demonstrations that showed his ability to break whiskey bottles with his bare hands surprised American viewers and earned him the nick-name "The Divine Fist."

He was then challenged by two American professional boxers and one professional wrestler and he defeated all three. From that time onward, he has traveled extensively while teaching and giving lectures in America, Europe, and around the world. For the sake of trainees all over the world, he wrote: What Is Karate? in 1958 (which sold over 120 thousand copies); in 1964, This Is Karate (which sold 60 thousand copies in 2 years), and in 1970 Advanced Karate.

In 1958, he opened a branch in Hawaii, making this the first foreign Kyokushin Karate School outside of Japan. By 1960, there were already 72 branches in 16 different countries such as the United States and European countries.