Sei
A boy's name of Japanese origin with 7 recorded U.S. births.
Meaning & Origin
Only 7 babies have been named Sei in recorded U.S. history. That level of rarity means your child would almost certainly be the only one in their school, their workplace, and most rooms they walk into — a genuinely one-of-a-kind choice.
Sei is not in the current top 1,000 boy names nationally, making it an uncommon choice — though your state or community may differ.
Sei is a boy's baby name of Japanese origin, with multiple possible kanji — sei (誠) meaning 'sincerity,' (成) meaning 'to become, to achieve,' or (青) meaning 'blue, youth.' Japanese single-syllable names carry the weight of a carefully chosen kanji character, with each possible meaning shaping the name's identity.
Rare in U.S. records, Sei is a name of maximum simplicity and genuine depth — a single syllable that, depending on its kanji, can mean sincerity, achievement, or the blue of a clear sky.
EtymologyShow more
Sei first shows up in U.S. Social Security records in 2007. A twenty-first-century entry, Sei belongs to the newest generation of American names — often coined, blended, or borrowed from international sources.
Its Japanese classification suggests a path from japanese linguistic traditions into American usage, though the specific route — whether through immigration, literature, or cultural exchange — would require deeper historical research.
At a Glance
Popularity Over Time
Sei has 1+ years of history in the U.S., first appearing in 2007.
Popularity by Decade
| Decade | Births | Avg Rank | Trend |
|---|---|---|---|
| 2000s | 7 | #10707 | — |
The Story of Sei
A Gen Z name
Peaking in 2007, Sei is a name that defines a generation. Boys named Sei are most likely born between 2007 and 2007.
How rare is Sei?
With fewer than 500 recorded births, Sei is an exceptionally rare name — a one-of-a-kind choice.
The journey through the decades
First appeared in the records in 2007, peaked in the 2000s with 7 births that decade.
Year-by-Year Data
View complete yearly data(1 years, 2007–2007)
| Year | Births | Rank |
|---|---|---|
| 2007 | 7 | #10707 |
Source: U.S. Social Security Administration. Showing years with 5+ recorded births.
Frequently Asked Questions
Is Sei a boy's or girl's name?
When was Sei most popular?
How popular is the name Sei?
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Data source: U.S. Social Security Administration, 2007–2007