Rei sits next to 4 phonetic neighbors — Ray, Rae, and Rye are the closest matches by sound. Most share Rei's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"courtesy, respect, gratitude"
"gracious, merciful"
"modern American creation, strong settlement"
"courteous, well-bred, polite"
"lion man"
"God's friend, divine companion"
"cultivator, earth worker"
"city of fashion and elegance"
"powerful, mighty"
"imperial authority"
"one who carries Christ within"
"champion, victorious one"
"from Luca, of the light"
"son of Ben"
"Yahweh has raised"
"fire brand, flaming sword"
"guardian, watchman (from Samaria)"
"God will strengthen, God strengthens"
Similar sound: These names share phonetic patterns with Rei — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese kanji 礼 origins, giving them the same cultural heritage as Rei.
Rhythm: Rei is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.