[1] Díaz Castro spent almost 60 years as a journalist, working for such newspapers and magazines as Prensa Libre, Hoy, La Tarde, Bohemia, Revista Trabajo, La Gaceta de Cuba, and Los CDR beginning in 1964.

[3] In 1972, Díaz Castro traveled to Japan, where she married a Japanese man, and while there she came to oppose socialism and especially communism.

[7][8] In 1987 she joined the Movimiento de los Derechos Humanos, led by Ricardo Bofill Pagés [es], and became a founding member and secretary-general of the organization's party, the Partido Pro Derechos Humanos, which called for Fidel Castro to announce a plebiscite.

[1][2][3] For over 20 years, she was a founding editor and contributor at the news site Cubanet, for which she is considered a pioneer of independent journalism in Cuba.

[1][2][3][4] Díaz Castro was married three times—to Guillermo Rivas Porta, Ricardo Villares Fernández, and Masayoshi Kaizuka—and had three children.