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Globally, Сей (Say
, Sei
, Sej
) is a common epicene first name. The forename Сей is habitual in Mongolia, where it is quite a common epicene name, Tunisia, where it is quite a rare unisex name, and Algeria, where it is quite a rare mostly boy's, but uncommonly feminine name. Not in comparison with a country's population, it most frequently occurs in India, Indonesia, and Mongolia. Also, Сей is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Say | Myanmar, Turkey, India, Guatemala, Indonesia |
| Sei | Myanmar, Turkey, India, Japan, Indonesia |
| Sej | Philippines, Malaysia, India, Indonesia, United States |
| Сей | Kazakhstan, Russia, Kyrgyzstan, Belarus, Ukraine |
Сей is also a name for the fictitious and mythical characters: Sei Asagiri , the fictional character from VA-11 HALL-A: "devoted Valkyrie of the White Knights, a band of para-military enforcers keeping the tenuous peace in Glitch City".