Sosai Oyama was born on July 27, 1923 in the south-west of Korea. His original name was Hyung Yee Choi. He lived his childhood in aristocratic family, spending his days mostly swimming, sporting and fishing with his friends. The young man was not really interested in his schoolwork. He preferred a martial art named Chabee. Chabee is mixture of Chinese and Korean martial arts, favored on Chinese hand techniques. His teacher was a man name Yi. This forty years old man worked for his father at the Choi's family estate. They practised Chabee together for four years. At a age of thirteen Hyung moved to Seoul to begin Junior High School.