Nishi Kōichiro is a Japanese actor who is affiliated with CES. He played the role of Ryoga Hakua (Aba Red) in the 2003 Super Sentai TV series Bakuryū Sentai Abaranger. Nishi debuted in 2002 through the model activities. In 2003, he starred in Bakuryū Sentai Abaranger as Ryoga Hakua/Aba Red. In 2014, Nishi reprise his role as Ryoga Hakua/Aba Red in the film, Zyuden Sentai Kyoryuger vs. Go-Busters: The Great Dinosaur Battle! Farewell Our Eternal Friends, for the first time in nine years since Tokusou Sentai Dekaranger vs. Abaranger. In May 5, 2015, he was married. (오뜨랑에서 실시간으로 번역된 한글 프로필도 확인할 수 있어요) 2025년 신 도쿄 수상경찰에 출연했다. 2025년 NEW GENERATION THE LIVE ウルトラマンアーク編 〜果てなき想像力の先へ〜에서 伴博志 역을 맡았다. 2025년 ウルトラマンアークTHE MOVIE 超次元大決戦!光と闇のアーク에서 Hiroshi Ban 역을 맡았다.