Sakai sits next to 4 phonetic neighbors — Kai, Saki, and Zaki are the closest matches by sound. Most share Sakai's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"boundary, border"
"intelligent, wise"
"glorious ruler"
"dragon"
"enlightened rice (kanji: 悟飯)"
"shrine maiden (ceremonial)"
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"star"
Similar sound: These names share phonetic patterns with Sakai — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese origins, giving them the same cultural heritage as Sakai.
Rhythm: Sakai is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.