THE NAME REPORT · FIRST-NAME VIEW

Kasai

NAME PROFILE

  1. Pronunciation & Spelling

    Easy for most readers

    The first read is the main source of friction: the spelling gives readers more than one plausible route to the pronunciation.

    85/100

  2. Everyday Use

    Low risk

    The main everyday ambiguity is name-to-name confusion: listeners can reasonably hear a nearby familiar name instead.

    93/100

  3. Lifetime Fit

    Strong lifetime fit

    Living use is noticeably weighted toward a narrower generation rather than spread evenly across age groups.

    80/100

  4. International Mobility

    Travels well, with one adaptation

    The same spelling can be voiced differently across language markets, so pronunciation is less stable internationally than the written form.

    90/100

NAME DETAILS

CLOSE SPELLINGS
Kasei

Popularity

Distinctive

#639

Uncommon in current U.S. usage.

U.S. SSA · Boys' names · 2025

Ranked number 639 of 1000 among boys' names in United States for 2025. Public familiarity band: Distinctive. Popularity describes familiarity, not name quality.

About the name

Kasai has no single documented origin or meaning that this project can confirm. It could plausibly draw on a Japanese surname (itself of disputed/unexplained kanji meaning across the sources checked), the Kasai River/province region of Central Africa (whose name has no documented linguistic derivation in the sources checked), or function as an independently coined US given name. Readers should not treat any one of these as the confirmed source without a family's own account.

Origin and history

河西 / 葛西 / 笠井 (Japanese surname kanji, meaning disputed across sources); Kasaï (French, river/province name).

Style through life

As an adult given name in the US, Kasai reads as distinctive and geographically/culturally ambiguous - it can suggest Japanese heritage to those who recognize the surname, or read as a fully invented modern name to others, without a single settled association. Phonetically simple and easy for a child to say and spell in English, though as a given name (rather than a surname) it has no established pronunciation convention or nickname tradition documented for US usage.

Regional and cultural use

Official U.S. birth-registration data shows this name had the largest single-year popularity increase of any boys' name nationally in a recent year — rising more than 1,100 rank positions to enter the national top 1,000 for the first time. No dataset currently establishes a meaning or origin for this name.

Worth knowing

Commonly mispronounced as KAY-sigh.

Bottom line

Kasai is workable on its own, with one trade-off worth testing before you settle on it. A useful final check is simple: let a fresh reader see the name once, without coaching, and listen to the first pronunciation.