Cognomen 南森 (南森 
, Nansen 
, Nanson 
) , in the world, is quite a rare last name. The family name 南森 is characteristic of Northern Europe, particularly Isle of Man, where it is quite a rare surname, Denmark, and Norway. Not in comparison with a country's population, the name is most common in Japan, the United States, and the United Kingdom. Much less frequently, 南森 is the forename as well as the last name.