Kai sits next to 4 phonetic neighbors — Kay, Kye, and Ky are the closest matches by sound. Most share Kai's Hawaiian cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"sea, ocean"
"goddess, divine woman"
"God has answered"
"light, bright, shining torch"
"little red one"
"my God is an oath, pledged to God"
"rising, ascending"
"curly-haired, descendant of Caiside"
"glowing ember, smoldering fire"
"famous ruler"
"clear and beautiful"
"jovial, cheerful, good-humored"
"son of Carr, marsh dweller's son"
"dark, black"
"from the city of Laurentum"
"moon"
"not intoxicated"
"pet form of Sarah"
"my God is the Lord (via Hebrew Elijah)"
"elf ruler with feminine suffix"
"friend"
Similar sound: These names share phonetic patterns with Kai — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Hawaiian origins, giving them the same cultural heritage as Kai.
Rhythm: Kai is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.