Tu sits next to 4 phonetic neighbors — Sue, Lou, and Rue are the closest matches by sound. Most share Tu's Vietnamese-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"beautiful; elegant"
"invented name combining lake + sha suffix"
"earth, ground"
"shy, refined"
"glory, honor"
"lake, waterfall"
"salt lake"
"land of the Bretons, from Brittany France"
"blend of Marley (pleasant meadow) and Lena (light, torch)"
"beloved, dear one"
"the crown opens the way, royalty paves my path"
Similar sound: These names share phonetic patterns with Tu — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Vietnamese origins, giving them the same cultural heritage as Tu.
Rhythm: Tu is a 1-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.