Kansai Ki-in
Cho began learning Go at the age of four and passed the test for becoming a professional in 1962. In 1963, Cho was invited to Japan. Originally intended to study under Minoru Kitani, Kensaku Segoe took Cho under his tutelage. Segoe was responsible for bringing Go Seigen to Japan and also teaching Utaro Hashimoto, founder of the Kansai Ki-in. Cho was considered a 2 dan professional in Korea, but was demoted to 4 kyu upon arriving in Japan.