Martial arts
In 1998, Koyamada began training in traditional Japanese karate under a karate instructor in Okayama, Japan, on weekends. After just a few months of training, he competed in the high school division of a national karate championship in Nagano. In 2000, before moving to Los Angeles, he earned his first-degree black belt in karate in Okayama. In high school, he took Judo as part of the school's physical education classes.
In 2000, shortly after moving to the United States, Koyamada began training in Northern Shaolin Kung Fu in Los Angeles six days a week. After six months of training, he started competing in local kung fu championships, winning first place and earning gold medals at several national martial arts championships in San Diego, San Francisco, and Las Vegas. In 2002, during the filming of The Last Samurai, Koyamada trained daily in horseback riding and Kyudo for nine months in Los Angeles, Japan, and New Zealand to eventually master Yabusame.
In 2004, Koyamada was featured on the cover of the Black Belt magazine. Later, he began training in Tae Kwon Do at a studio inside the CBS Studios lot under a traditional Korean instructor in Los Angeles, practicing every other morning. He earned his black belt in 2005. His classmate included an American bassist and composer Stanley Clarke. In 2005, Koyamada trained under Tadashi Yamashita for Iaido and Aikido at the Aikido Center of Los Angeles under a Japanese American Aikido instructor in Downtown Los Angeles.
In 2008, Koyamada began training in Kung Jung Mu Sul, the Korean Royal Court Martial Arts, under a Korean grand master in San Francisco. After a year of training, he earned a brown belt and eventually earned his first-degree black belt after two years of dedicated practice. In 2009, Koyamada was invited to perform Japanese Iaido at the first-ever Martial Arts Tour, a national martial arts festival in Nettuno, Italy, which was broadcast nationally across Italy.
In 2010, Koyamada created the first-ever United States Martial Arts Festival (USMAF), an international martial arts event hosted by KIF USA. The festival aimed to bring together various martial arts disciplines from countries where these arts originated, held at the Redondo Beach Performing Arts Center in Redondo Beach, California. The event attracted over 1,000 participants, including grandmasters, masters, instructors, students, MMA fighters, celebrities and supporters. In 2011, the event was co-hosted by the Japan Foundation and sponsored by the City of Kyoto to promote traditional Japanese culture, including flower arrangement, Japanese calligraphy, and tea ceremony.
