Born on June 20, 1950, in Hinokage-cho, Miyazaki Prefecture, as the fourth son of seven children. He became interested in martial arts from an early age, and after graduating from high school, entered the Kyokushin Kaikan Honbu Dojo (formerly Headquarters) in Ikebukuro, Tokyo. He learned the essence and techniques of the Kyokushin Spirit under the guidance of the late Kyokushin Kaikan President Sosai Masutatsu Oyama and other Kyokushin lions. He took full advantage of his blessed physique and suddenly captured third place at the 9th All-Japan Tournament in 1977. His astonishing performance and placement immediately placed Nakamura on the map of Kyokushin. In May 1979, he defeated his formidable opponent, Keiji Sanpei, in the final and won the 11th All Japan Karate Championship.
Winning the All-Japan title placed him in the national team to represent Japan in the upcoming world tournament. To achieve his absolute goal of defending the karate title for his home country, Japan, he forced himself into harsh environments and experienced training overseas in countries such as the United States and Africa. Then, the 2nd World Karate Championships was held in November 1977. The overseas fighters have made great strides in quality and quantity. Their techniques have improved to a level incomparable to the first tournament four years ago. As the Japanese fighters were defeated one after another, the threat of international fighters became apparent at the Budokan. In the third round on day 2, he struggled against an unknown fighter from Sweden. Hans Dolph Lundgren, a tall athlete with a brown belt, was unfazed by the powerful thrusts of the All-Japan champion and continued to use his leg techniques to develop an evenly matched fight. Although Nakamura managed to get through the extension round and eventually won a victory, it was a heart-wrenching match. In the quarter-finals, he faced Koichi Kawabata and won the match. In the final, he fought Keiji Sanpei and overcame the opponent for the third time. It was the moment that Nakamura, \"Kyokushin\'s Heavy Tank\", captured the world championship title.