Surname Нагаока (Nagaoka 
, Нагаока 
) , around the world, is quite a rare family name. The last name Нагаока is habitual in Paraguay, where it is quite a rare surname, Japan, where it is a rare surname, and Brazil. Measured by absolute frequency, it is commonest in Brazil, Japan, and the United States. Very seldom, Нагаока is the forename as well as the last name.