Surname Riuichi (Riuichi 
) , around the world, is a very rare cognomen. The cognomen Riuichi is characteristic of Eastern Asia, particularly China, where it is an extremely rare surname. Much more frequently, Riuichi is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Riuichi | Japan, China, Spain, United States, Brazil |