(written from a Production point of view)
She was born as Momoko Iwamatsu in New York as the daughter of children's book authors, Taro Yashima (pseudonym of Jun Atsushi Iwamatsu) and Mitsu Yashima (pseudonym of Tomoe Iwamatsu). The girl in her parents' picture book, "Momo's Kitten" (1961), was based upon her. Momo is the sister of the late actor Mako, and wife of Ralph Brannen. She is also a well known stage actress.
Yashima has guest starred in television series such as The Beverly Hillbillies (1971, with Miko Mayama), Ironside (1974, with Barry Atwater, Joan Pringle, William Shatner, Paul Sorenson, and Mario Roccuzzo), M*A*S*H (1973, 1976, and 1979, with David Ogden Stiers in the latter one), Falcon Crest (1984, with Robert Foxworth, Whit Bissell, Bill Erwin, Liam Sullivan, and Kenneth Tobey), Street Hawk (1985, with James Avery, Robert Beltran, Christopher Lloyd, Lawrence Pressman, Brian Thompson, Biff Yeager, Robert Costanzo, and Paul Eiding), Babylon 5 (1994, with Andreas Katsulas, Bill Mumy, Julie Caitlin Brown, and Clive Revill), Moesha (1997), and Six Feet Under (2003, with Gary Bristow, Joanna Cassidy, James Cromwell, Peggy Miley, and her stunt double Boni Yanagisawa).
She has also appeared in films such as Farewell to Manzanar (1976, with Clyde Kusatsu), Charlie Chan and the Curse of the Dragon Queen (1981, with Brian Keith and Henry Kingi, Sr.), Blind Date (1987, with John Larroquette, George Coe, Georgann Johnson, Armin Shimerman, Brian George, Mike Genovese, and Dick Durock), Ulterior Motives (1992, with Craig Shugart), and Ravager (1997, with Stanley Kamel and Robin Sachs).