Cognomen Osamumasaru (Osamumasaru 
) , in the world, is a very rare surname. The cognomen Osamumasaru is habitual in Eastern Asia, particularly Japan, where it is a very rare surname. Much more frequently, Osamumasaru is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Osamumasaru | Japan |