Roderick T. Kobayashi was born in Hawaii and raised in Japan by his grandfather who was a Buddhist priest. Since his youth, he had been deeply involved in learning the history and philosophy of budo (Japanese martial arts).
He was first introduced to Aikido by his father who had great influence in inviting Master Koichi Tohei, who was then Chief Instructor of Aikido at the Aikido World Headquarters in Japan, to Honolulu in 1953. However, his formal training in Aikido did not start until 1957, after his 3 years of military service. His first teachers at the Hawaii Aikikai were master: Yukiso Yamamoto, Kazuto Sugimoto, and Isao Takahashi. These masters were the first students of Tohei Shihan, the foremost authority on Aikido and Ki in the United States. Each of these masters was unique in his own way, and had a great influence in Kobayashi's understanding of Aikido and Ki.
Kobayashi's training with Master Tohei began in 1961. He trained under Tohei Sensei whenever possible in Japan, Hawaii and the continental U.S. He received his Shodan (1st degree black belt) in 1962, Nidan (2nd degree) in 1965, and San dan (3rd degree) in 1966. After becoming a full time professional Aikido instructor in the fall of 1968, he was promoted to the rank of Yondan (4th degree). He was also appointed as one of the two non-Japaneese nationals to receive the rating of Hombu Shidoin, instructor of Aikido for the Aikido World Headquarters, Tokyo, Japan. He assumed the responsibilities of the President and Chief Instructor of the Western States Aikido Federation until 1974. He was promoted to the rank of Godan (5th dan) in January, 1972. In September, 1973 Kobayashi was promoted to Rokyudan (6th degree), or master teacher.