Jun sits next to 3 phonetic neighbors — Juan, John, and Joon are the closest matches by sound. Most share Jun's Chinese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"king, lord"
"flame, bright"
"sun"
"beautiful fragrance"
"mythical dragon-unicorn creature"
"flower sound"
"bright, brilliant, clear"
"mother"
"nautical mile, measure of sea distance"
"increase, wisteria"
"Mexican, from Mexico"
Similar sound: These names share phonetic patterns with Jun — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Chinese origins, giving them the same cultural heritage as Jun.
Rhythm: Jun is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.