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.