Ito was born in Los Angeles to Jim Ito and Toshi Ito. Both his parents were kept in internment camps for Japanese Americans with their families during the Second World War. Ito was enrolled in Sunday School at the Mount Hollywood Congregational Church. Ito attended John Marshall High School, where he was student body president and received the Scholar Athlete award in 1968. He earned his bachelor's degree with honors from the University of California, Los Angeles in 1972, and his J.D. degree from the University of California, Berkeley Law School in 1975. He then joined the Los Angeles district attorney's office in 1977, working in the hardcore gang unit and the organized crime and terror unit, among others.