He became a professional judoka under the sponsorship of Keiyo Gas and competed at national and international level, placing third at the Japanese championships at 100+.
His first apparition in the promotion was specially notable for his entrance and attire choices, coming to the cage wearing an ornated kimono, a jingasa hat and a gas mask before taking them off to reveal floral print shorts.
Nakamura debuted at Sengoku: Fifth Battle as an entrant in the inaugural Middleweight Grand prix eliminating British Paul Cahoon.
Kazuhiro Nakamura defeated fellow countryman Yuki Sasaki via unanimous decision and booked a spot later that evening in the final.
Nakamura Returned at Sengoku: Ninth Battle in a title eliminator that saw the winner rematch champion Jorge Santiago.
On February 16, 2013, Nakamura defeated Young Choi to win the vacant DEEP Middleweight Championship which is the first title of his career.
On July 21, 2014, Nakamura faced Seigo Mizuguchi at DEEP: Cage Impact 2014 and won via second round corner stoppage.
[6] On February 22, 2014, Nakamura made a one-off professional wrestling appearance for the Wrestle-1 promotion, teaming with Masakatsu Funaki, Manabu Soya and Seiya Sanada in an eight-man tag team match, where they defeated Desperado (Masayuki Kono, Kazma Sakamoto, René Duprée and Ryouji Sai).