is a Japanese kickboxer who competes in the lightweight division. After beginning his career as a featherweight in 2002, Yamamoto became a mainstay in the All Japan Kickboxing Federation and first challenged for the AJKF Featherweight Championship in December 2004 when he fought to a draw with Genki Yamamoto. He then went on a hot streak in 2005, winning the IKUSA 2005 –60 kg Grand Prix in the process, and was given another chance at the AJKF Featherweight title in January 2006 when he beat Genki Yamamoto in a rematch to take the belt. The following years saw Yamamoto move up to lightweight and have more domestic success as he took the AJKF's Best of 60 kg Tournament 2007 and the Krush Lightweight Grand Prix 2009 before he emerged internationally with the It's Showtime promotion. He lost to Sergio Wielzen in his first attempt at the It's Showtime 61MAX Championship in December 2010 but came back to win the belt in July 2012 by defeating Javier Hernandez.
Career
Early career
Yamamoto began practicing Kyokushin karate as a schoolboy and won the all-Japan junior high school full contact karate championships in 2000, followed by the high school championships the following year. He would later begin kickboxing under the legendary Toshio Fujiwara at the Fujiwara Gym in Tokyo, and debuted professionally with a unanimous decision win over Hideki Shimizu at AJKF: Golden Trigger on September 6, 2002.
After amassing an undefeated record of 7-0-2 fighting in the All Japan Kickboxing Federation, Yamamoto was invited to compete in the promotion's Strongest Lightweight Tournament 2004. Having defeated Hiromasa Masuda by unanimous decision at the tournament's opening round on March 13, 2004, he then tasted defeat for the first time at the hands of the eventual tournament winner, Tsogto Amara, when he lost a majority decision in the quarter-finals on April 16, 2004.
He rebounded with three straight victories to earn himself a shot at the AJKF Featherweight (-57 kg/126 lb) Championship against Genki Yamamoto at the Fujiwara Festival 2004 on December 5, 2004. After five rounds of fighting, the bout was called a draw, meaning Genki kept the title.
Domestic dominance
2005 saw Yamamoto wear gold for the first time in his career by winning the IKUSA 2005 –60 kg/132 lb Grand Prix. A first round knockout of Koishiwara at the quarter-final stage on June 18, 2005 was followed up by a points victory over Tomohiro Oikawa in the semis and then a technical knockout win against Naoki Ishikawa in the final on the same night three months later as Yamamoto claimed the crown. This led him to a rematch with Genki Yamamoto for the AJKF Featherweight title on January 4, 2006 at the New Year Kick Festival 2006, where he won a majority decision and became the new Japanese champion.
Yamamoto then went through a rough patch, however, as he went 2-3-1 in his next six fights with all three losses against Thai opposition. At the end of 2007, he was given the chance to get back on track by entering the AJKF's Best of 60 kg Tournament 2007. A second-round knockout of Susumu Daiguji on August 25, 2007 sent him into the semi-finals two months later where he took a unanimous points victory over Naoki Ishikawa, in what was the third fight between the pair. Later that night, Yamamoto defeated Haruaki Otsuki by the same margin in a five-round affair to emerge as Japan's top kickboxer at 60 kg/132 lb.
On January 4, 2008, he made the first and only defence of his AJKF Featherweight strap by knocking Yosuke Mizuochi out with a high kick in round four at the New Year Kick Festival 2008. After being stopped by Muay Thai exponents PKP Rachanon F16 and Wanrop Weerasakreck in his next two outings, he then returned to winning ways with four consecutive victories which earned him a call up to fight on kickboxing's biggest stage, K-1. Making his promotional debut at the K-1 World MAX 2009 World Championship Tournament Final 16 in Fukuoka, Japan, on April 21, 2009, Yamamoto outpointed Yuki to a unanimous judges' decision after flooring his opponent with a knee strike in the third and final round.