Kei sits next to 3 phonetic neighbors — Kay, Kai, and Rey are the closest matches by sound. Most share Kei's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"joy, jubilation"
"ray of light and land"
"speckled, freckled"
"joyful celebration, festivity"
"cup, goblet"
"magnificent one"
"ever-powerful king"
"modern American compound of Jah (God) + Shawn"
"bold, brave"
"who is like God?"
"creative coinage blending Da- prefix and Kai (sea)"
"son of Jens (son of John)"
"son of encouragement"
"brave, vigorous power"
"strong, powerful"
"ray of light, counsel"
"victory of the people (via Nicasen interpretation)"
"the number seven"
"just, righteous, fair"
Similar sound: These names share phonetic patterns with Kei — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese kanji 慶 origins, giving them the same cultural heritage as Kei.
Rhythm: Kei is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.