His effective punching and kicking combinations helped him reach the finals of six All Japan Tournaments in a row, winning four of these to break Keiji Senpai's record.
He also reached the finals of two World Open Tournaments where he lost to Francisco Filho on boards and Kenji Yamaki, training partner and fellow student of Tsuyoshi Hiroshige's Jonan Branch.
He had aspirations to become strong and as soon as he began elementary school, his father, who was also a Karate practitioner, pressured him to join the Kyokushin Kaikan General Headquarters Dojo.
After entering high school, he transferred to the Tokyo Jonan Kawasaki branch near his home and studied under Tsuyoshi Hiroshige.
At the time, Kazumi's only accolade was winning FTV Cup Tohoku Tournament in the same year, but was otherwise deemed as a unremarkable participant.
Although he lost to Yoshihiro Tamura in the final match, he won second place in his first appearance and was named the break-out sportsman of the event.
Kazumi on the other-hand had defeated Norihisa Horiike in the quarter-finals and Masaki Takao and the Hyogo branch in the semi-finals.
In 1997, he had cruised the 29th All Japan Championship without any real challenge, until reaching the finals, where Kazumi would fight Gary O'Neil again.
With 30 remaining in overtime, O'Neil would collapse following left side mawashi-geri kicks from Kazumi, having now won his third overall and second consecutive victory.
Opponents include Francisco Filho, Hitoshi Kiyama, Ryuta Noji, Yasuhiko Kimura, Masayoshi Takaku, Yoshihiro Tamura, Naoki Ichimura, Ryu Narushima, Shinji Adachi, who were selected as representatives of the 7th World Open Karate Championship.
At the 7th World Championship held in November of the same year, he defeated Glaube Feitosa in the semi-finals, advanced to the finals, and rematched with Filho.
Kazumi lost and become the runner, whereas Filho would be the first foreigner to win the Kyokushin World Championship in 27 years of its inception from 1975.
Hajime Kazumi is said to be humble and discreet, a spiritually and mentally strong person who doesn't put himself above others.
On 24 November 2002, Kazumi officially resigned from Kyokushin-kaikan (Kanchō Shokei Matsui) to join a new organization led by Hatsuo Royama and his instructor Tsuyoshi Hiroshige.
He later resigned from the newly established Kyokushin-kan organisation to become the leader of an independent group of dojos operating in the Tokyo area.
With Tatsuya Iwasaki, Kazumi is the author of Shinseki Real Karate Bible, a manual for instruction of full-contact kumite (fighting) with accompanying DVD.