Cognomen Ryuman (Ryuman 
) , in all the world, is a rare last name. The cognomen Ryuman is characteristic of Japan, where it is a rare surname, and the United States, where it is an extremely rare surname. Much less frequently, Ryuman is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Ryuman | Brazil, Spain, United States, Japan |