Tatsuo Yamada, who established "Nihon Kempo Karate-do", was interested in Muay Thai because he wanted to perform Karate matches with full-contact rules since practitioners are not allowed to hit each other directly in karate matches.
Yamada had already announced his plan which was named "The draft principles of project of establishment of a new sport and its industrialization" in November 1959 and he proposed the tentative name of "Karate-boxing" for this new sport. Yamada started studying with a Muay Thai champion, formerly his son Kan Yamada's sparring partner. Osamu Noguchi who was a promoter of boxing and was also interested in Muay Thai took the Thai fighter and developed a combined martial art of karate and Thai boxing and creating the term kick-boxing in the 1950s.
In 1963 three karate fighters from Oyama dojo (Kyokushinkai Karate) went to the Lumpinee Boxing Stadium in Thailand, and fought against 3 Muay Thai fighters winning two of the three bouts. The three fighters' names were Tadashi Nakamura, Kenji Kurosaki and Akio Fujihira (also known as Noboru Osawa).
The original kick-boxing allowed throwing and butting in the beginning to distinguish it from the Muay Thai style, although this was later dropped. The Kick-boxing Association, the first kick-boxing sanctioning body, was founded by Osamu Noguchi in 1966 soon after that. Then the first kickboxing event was held in Osaka on the 11th April 1966. Tatsu Yamada died in 1967; his dojo changed its name to Suginami Gym, and kept sending fighters off to support kick-boxing. Kick-boxing boomed and became popular in Japan as it began to be broadcast on TV. Tadashi Sawamura was an especially popular early kick-boxer. However, the boom finished and became unpopular after Sawamura was retired. In 1993 Kazuyoshi Ishii (founder of Seidokan karate) produced K-1 under special kick-boxing rules (No elbow and neck wrestling), kickboxing had become famous again.
The sport has spread through Europe, North America, Australia and New Zealand. There are many martial arts labeled as kickboxing including Japanese boxing, American kickboxing, Indian and Burmese boxing, French Savate and Muay Thai. Many of these and other styles do not consider themselves to be 'kickboxing', although the public often uses the term generically to refer to all these martial arts.