She apparently came down with pneumonia, recovered enough to return to the set, then died from an unrelated heart problem.
Her co-star in "Karate Kid II," Tamlyn Tomita, was also in the cast of "Gaijin II," about Japanese immigrants in Brazil.
According to press reports, McCarthy was born Nobu Atsumi in Ottawa, Canada, then raised from infancy in Japan. She became a successful model and won the title Miss Tokyo.
A memorial service was held in Los Angeles' Little Tokyo on April 19. Pat Morita attended and spoke to those assembled.
Her credits include "The Geisha Boy," "Wake Me When It's Over," "Walk Like a Dragon," telefilm "Farewell to Manzanar" and indie film "The Wash." She also served as the artistic director of L.A.'s East West Players, America's first Asian-American theater company; she served as its its artistic director 1993.