He is the former K-1 Heavyweight Champion and successfully defended the title against kickboxing legend Peter Aerts at K-1 World Grand Prix 2010 in Yokohama.

Kyotaro entered the world of K-1 when he fought and won the K-1 Tryout 2007 Survival tournament in Tokyo by defeating Tatsunori Momose in the semi-final and Takumi Sato in the final, all by decision.

Kyotaro was then invited to fight in the K-1 World GP 2008 in Fukuoka in which he became the runner up losing to Brazilian Karateka Ewerton Teixeira.

On March 28, 2009, Kyotaro won the K-1 Heavyweight (-100 kg) Title tournament by knocking out Melvin Manhoef in semifinals and beating Gokhan Saki in finals by extra round majority decision.

Kyotaro withstood the Frenchman's early power to give him a severe beating in the 3rd round to earn a draw.

[10] Kyotaro was scheduled to face the J-Network heavyweight champion Hidenori Sakamoto at K-1 World GP 2022 Japan on February 27, 2022.

[12] He won the fight by a second-round technical knockout and advanced to the tournament semifinals, where he faced Hisaki Kato.

[14] Kyotaro faced the unbeaten Satoshi Ishii in a super heavyweight bout at K-1 World GP 2023: K'Festa 6 on March 12, 2023.

[16] Kyotaro debuted as a pro boxer on December 31, 2011, when he took a unanimous decision win over Michael O'Donnell in Osaka, Japan.