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Home › Baby Names Directory › Kaisei

Kaisei

♂ Boy

Pronounced KY-say /ˈkaɪ.seɪ/Medium

Meaning: From the Japanese Kaisei — variously written 'reform/restructure' and 'the open sea/world', depending on the kanji; routes layeredLow

In 30 seconds: Reform; the open sea: Kaisei is Japanese. Crisp, modern, and warm (said 'KY-say').
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Origin LowJapanese
MeaningFrom the Japanese Kaisei — variously written 'reform/restructure' and 'the open sea/world', depending on the kanji; routes layered
U.S. rank (2025)#11319 ↘ Falling
2025 U.S. births6 boys (0.00% of U.S. boys)
Peak year2007
Total births (all-time)≈ 137

Popularity in the U.S. · SSA data

peak 200720052025

U.S. births per year (Social Security Administration, 1880–present). Pink marker = peak year.

SSA data updated May 2026. How we source & verify this data.

History & Origin

Kaisei comes from the Japanese Kaisei — variously written 'reform/restructure' and 'the open sea/world', depending on the kanji (routes layered, which we note). A crisp, modern name (said 'KY-say').

In the U.S. it appears in Japanese families. Rare, reform-and-the-sea at the root, and crisp.

Did you know? Kaisei is variously written 'reform/restructure' and 'the open sea/world' in Japanese, depending on the kanji — a crisp, modern name (the routes are layered, which we note; said 'KY-say').
Overall data confidence 34%
References — Kaisei — routes layered

Variations

KaiseKaiseih

Nicknames

Kai

Famous Bearers

  • Famous bearers coming soon.

If you like Kaisei…

Kaito— a kin Kai- Japanese boys' name
Sora— a fellow Japanese boys' name
Ren— a companion Japanese boys' name
Koi— a fellow Japanese choice
Kanon— lands in the same popularity range

Explore names like Kaisei

By themeuncertainjapanese
By meaningSea / Water

All themes →All meanings →All origins →

Frequently Asked

What does the name Kaisei mean?

Kaisei is Japanese, variously 'reform/restructure' and 'the open sea/world' (depending on the kanji); the routes are layered.

How do you pronounce Kaisei?

It's said KY-say /ˈkaɪ.seɪ/ — two syllables, stress on the first.

Is Kaisei a boy or girl name?

Kaisei is a boy's name.

How popular is Kaisei?

Kaisei is a very rare name in the U.S.

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