Cognomen Hironaga (Hironaga 
) , in the entire world, is a rare last name. The cognomen Hironaga is characteristic of Brazil, where it is a very rare surname, the United States, and Canada, where it is an extremely rare surname. In absolute terms, it is the most numerous in the United States, Brazil, and China. More prevalently, Hironaga is the forename as well as the last name.