Cognomen Seijun (Seijun 
) , globally, is a rare last name. The last name Seijun is characteristic of Eastern Asia, particularly Japan, where it is a very rare surname, and China, where it is an extremely rare surname. Likewise, Seijun is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Seijun | Brazil, Japan, India, China, Puerto Rico |