Pancrase Genki started his professional career in 1998, when he fought
Tiki Ghosn in Extreme Shoot 2. Then he moved to japanese promotion
Pancrase, defeating Kosei Kubota by unanimous decision in his first fight. He joined
Sanae Kikuta's Grabaka team to further develop his skills. Sudo became well known for his particularly flashy choreographed ring entrances that often included costumed dancers. One entrance featured Sudo doing
the robot and operating levers that released a column of smoke from the top of his head while wearing a
Kentucky Fried Chicken bucket as a hat and a white plastic mask, in an homage to the musician
Buckethead. On 21 December 2001, Sudo fought against
Kenichi Yamamoto at
Yokohama Cultural Gymnasium, and won by
Rear Naked Choke. Prior to the match, Sudo and Yamamoto promised to bet Yamamoto's
UFC championship belt on the outcome. Following his win, Sudo was given the belt by Yamamoto, and Sudo was introduced as "
UFC Japan Champion" by media after this bout. As the bet was personal, he is not sanctioned as champion by
Zuffa.
UFC Sudo had his debut in
Ultimate Fighting Championship at UFC 38, facing Leigh Remedios. Making his entrance in a kimono and a
tengu mask, Sudo showed his personal style by dancing and throwing spin kicks to open the match, eventually launching a flying triangle choke attempt which lasted for most of the round. At the second round, Genki threw Remedios with a hip throw and locked a
rear naked choke, making him tap out. The Japanese wrestler then posed with a flag of all the nations and proclaimed his catchphrase of "We Are All One" for a crowd pop. He returned at
UFC 42 against
Duane Ludwig. Again Sudo showed his theatrical side, walking backwards towards Ludwig and doing the robot dance before taking him down. However, despite his initial domination, the Japanese started receiving damage while standing, failing in a rolling kneebar and several takedown attempts. Sudo came back at the last round, taking down Ludwig and pounding and bloodying him with punches and elbows. Whilst Ludwig was taking a beating, referee John McCarthy interrupted and stood the two fighters up to check on Ludwig's nose. When the doctor allowed the fight to resume they did not restart from the same previous dominant position held by Sudo. Ludwig took advantage of the indirect rest given to him and avoided, with the aid of the referee's decision, the unfavorable position that he was in. He dominated the end of the fight landing hurtful shots on Sudo to win a split decision. Ludwig mocked Sudo after the final bell with a
crane kick pose. Sudo's last fight in UFC would be against the debuting
Mike Brown in
UFC 47. Brown tried to capitalize in Sudo's confusing moves by rushing him against the fence, managing to slam him on the mat, but Sudo then locked a triangle choke and transitioned into an armbar for the tap out.
Hero's Genki Sudo was defeated by K-1 HERO's
lightweight champion Norifumi "Kid" Yamamoto. The fight was won by a controversial referee stoppage after Sudo was knocked down by a right hand which was followed by some punches. At K-1 Dynamite! on 31 December 2006 he defeated Damacio Page by
submission. After his win, and to the shock of the crowd, Sudo announced his retirement.
After retirement Prior to his retirement on New Year's Eve Sudo fought for K-1 HERO's, the
mixed martial arts branch of the most popular Japanese
combat sports circuit. In 2008, he accepted the position of Manager for
Takushoku University's
wrestling team. In the 2009 Eastern Japan University League Games, the 2009 All Japan University
Greco-Roman Championship Tournament, and the 2010 All Japan University
Wrestling Conference, he was awarded the prize for Best Manager. In addition, he led the team to victory in the 2010 All Japan Student Wrestling Championship, and in his second year as manager
Takushoku University was victorious at all four of the biggest student
wrestling tournaments. In 2010, he was made the Japanese representative manager for the World University Championship. Sudo was cast in
Kamen Rider W Forever: A to Z/The Gaia Memories of Fate (仮面ライダーW（ダブル） FOREVER AtoZ／運命のガイアメモリ) in 2010 as Kyosui Izumi, member of NEVER and user of the T2 Luna Memory. He reprised his role in
Kamen Rider Eternal, in
Kamen Rider W Returns which was released on 21 July 2011. He has also finished filming his part of the movie The R246 Story. On 8 April 2010 he received his
black belt in Brazilian Jiu-jitsu under Naoyoshi Watanabe at Triforce Academy. ==Kickboxing career==