🇯🇵🇬🇧 lead actor in the Cinemax and HBOMax series Warrior.
Born in 1987, Koji grew up in Epsom, Surrey. His father is Japanese and his mother is English.
Koji started in the industry doing extra work and making short films as a teenager. At 18 he moved to Thailand while still training in martial arts and did some small jobs in that film industry. He subsequently worked in Japan's film industry for a few years, before returning to England to train at the Actors' Temple Studio in London. Eventually, Koji started getting more jobs in theatre and TV in the UK, where he stated, "my dual heritage has not particularly been advantageous. Opportunities for East Asian actors at the time was and still is quite limited although things are changing."
Koji dropped out of college at the age of 19 to focus on acting and martial arts. In his 20s, Koji studied and competed in taekwondo and trained in Shaolin kung fu at the Shaolin Temple UK. He has written and produced his own films, and has also worked as a stunt double; most notably on Fast & Furious 6. He has also performed with the Royal Shakespeare Company, at the Regents Park Open Theatre, Hampstead Theatre, Royal Court, Charing Cross, and Ovalhouse among others.
By 2017, Koji was discouraged by a recent lack of television roles and considering a career change. His agent and his mother convinced him to submit an audition tape for the lead role of Ah Sahm in the Cinemax series Warrior, which he secured.
Based on an original idea by Bruce Lee and produced by filmmaker Justin Lin, Warrior is centered around a martial arts prodigy in the late 1870s who emigrates from China to America in search of his sister, only to be drawn into the Tong Wars of San Francisco. In a nod to Lee's ethnic background, Ah Sahm is of partial European ancestry, which Koji found relatable and fitting for the character. The first season premiered in April 2019, and the second season premiered in October 2020.
In August 2019, Koji was cast as Storm Shadow for the upcoming Snake-Eyes movie. He was also cast in David Leitch's upcoming film Bullet Train.