Surname Mitsuo (Mitsuo 
, 三男 , 光男 , along with others...) , worldwide, is quite a common family name. The family name Mitsuo is habitual in Japan, where it is quite a rare surname, Hong Kong, where it is a rare surname, and Malaysia. Measured by absolute frequency, it is commonest in Japan, China, and Indonesia. Also, Mitsuo is the forename as well as the last name.