John got his start in the film business as a stunt man and then quickly began landing acting roles as well. He continues to set himself apart from the rest by providing the director the rare ability for an accomplished actor to truly perform his own stunts. Koyama has worked with several top industry directors in this way including: James Wan, Vince Gilligan, John Woo, Ivan Reitman, John Carpenter, James Foley and Edward Zwick.
At the age of 9, Koyama started studying boxing, kickboxing, gung fu, kali and escrima under Dan Inosanto and Richard Bustillo at the original Filipino Kali Academy in Torrance, California.
With over 100 acting/stunt credits to his name, John is also a highly sought after Stunt and Fight coordinator for television and feature film projects. He is best known for his work on Furious 7, The Twilight Saga Breaking Dawn, Total Recall, Hanna, Book of Eli and Breaking Bad.