Kageyama began his career in San Francisco as one of the original members of the Asian American Theatre Company. While in San Francisco he attended the American Conservatory Theatre. In 1979 Kageyama moved to Los Angeles where he joined the Asian American theatre group, East West Players (EWP), working not only as an actor, but also as a director and designer. In 1985 he received a Drama-Logue Award for Costume Design for EWP's Rashomon. In 1993, Kageyama directed The Grapevine, written by Grateful Crane Ensemble founder Soji Kashiwagi, produced at the Los Angeles Theatre Center. In spring 2001 Kageyama played Erronius in an all Asian American production of the musical, A Funny Thing Happened on the Way to the Forum at EWP in Los Angeles.
He has acted on many films, notably The Karate Kid, Part II, The Next Karate Kid and Gung Ho. He was also featured in the Golden Dreams film exhibit which opened the Disney's California Adventure theme park. He has appeared in many TV shows including Quantum Leap and Home Improvement.
Kageyama is heavily involved in community activity, often volunteering for various organizations. He has served as an emcee and directed shows for many charitible events. He is a docent at the Japanese American National Museum, where he does story telling for visiting children. He is also an animal advocate and helps place dogs in homes.
