Before joining ILM, Koyoma did character animations on the 2006 Korean film The Host for the visual effects company The Orphanage. His first project for ILM was the 2006 blockbuster Pirates of the Caribbean: Dead Man's Chest (featuring Lee Arenberg). Koyama's subsequent projects for ILM include Transformers (2007, written by Alex Kurtzman and Roberto Orci and featuring Andy Milder, Glenn Morshower, W. Morgan Sheppard, Michael Shamus Wiles, Jamison Yang, and the voice of Robert Foxworth), Rush Hour 3 (2007, featuring Tzi Ma), and Iron Man (2008, featuring Faran Tahir and Bill Smitrovich).