Cognomen 澄夫 (Sumio 
, 澄夫 ) , around the world, is quite a rare family name. The family name 澄夫 is characteristic of Japan, where it is quite a rare surname, Philippines, where it is a rare surname, and Singapore. Not in comparison with a country's population, this name is the most popular in Japan, Philippines, and China. More prevalently, 澄夫 is the forename as well as the last name.