Kazu Iijima was born in 1918 in Oakland, California, one of three daughters. Her parents met after emigrating from Japan; her father attended the University of California, Berkeley, and her mother traveled to California after the end of her first marriage. Iijima's father started a Japanese-language newspaper in which her mother published poetry. Iijima attended the University of California, Berkeley. During World War II, she was first forcibly removed to the Tanforan Assembly Center in San Bruno, California and then incarcerated at the Topaz War Relocation Center near Delta, Utah. She married Tak Iijima, in Salt Lake City, Utah. He was in the 442nd Regimental Combat Team at Camp Shelby in Hattiesburg, Mississippi. Iijima joined her husband in Hattiesburg when she began working at the segregated United Service Organization (USO) office there. In 1945 or 1946 she moved to New York City and edited the Japanese American Committee for Democracy newsletter. In 1948 she gave birth to a son and a daughter. Iijima was active in protesting the Vietnam War and co-founded a political group, Asian Americans for Action, in 1969 with Minn Matsuda.