He obtained a PhD at the UCM in 1993, reading a thesis about theSpanish-Japanese relations, 1937–1945.[2][3] Having lived inThailand, thePhilippines andJapan, he briefly worked as teacher of Spanish language for PrinceNaruhito in 1992.[4] He earned a PhD in theUniversity of Tokyo in 2007,[2][5] reading a thesis onThe Spanish Community in the Philippines, 1935–1939: The impact of the War in Spain and the preparations for Philippine Independence in its evolution and identity.
Because of his investigations, Rodao has been able to interview people from the World War II, such as ministerRamón Serrano Suñer, communist leaderSantiago Carrillo, ambassador Eikichi Hayashiya, spyÁngel Alcázar de Velasco or the Republican consul in Japan José Luis Alvarez Taladriz, as well as Japanese residents in Spain or members of the Spanish community in the Philippines, especially Anna Maria Aguilella, the only survivor of themassacre at the Spanish consulate in Manila in 1945.[6]