Ryo sits next to 4 phonetic neighbors — Rio, Leo, and Theo are the closest matches by sound. Most share Ryo's Japanese cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"dragon"
"universe, cosmos"
"celestial body"
"who is like God (form of Michael)"
"from Rome (Rum/Anatolia)"
"border market, trading post"
"enlightened rice (kanji: 悟飯)"
"shining, brilliant"
"lapis lazuli, flowing water"
"bright color, vitality"
Similar sound: These names share phonetic patterns with Ryo — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Japanese origins, giving them the same cultural heritage as Ryo.
Rhythm: Ryo is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.