The katakana name ウソップ (Usoppu) decomposes into two simultaneous readings:
uso 嘘 (Japanese for lie / falsehood) — Usopp’s surface character trait, established in his first chapter (chronic morning-prank, “THE PIRATES ARE COMING!!”).
Aesop イソップ (Isoppu) — the Japanese transliteration of the ancient Greek fabulist whose name is canonically associated with moral storytelling through invented tales.
The katakana spelling is itself the structural trick: written in kana, not kanji, the name ‘Ore wa Usoppu!’ can be heard as either “I am Usopp!” or “I am a lie!” The name IS the lie that is also a truth.
The father-line is encoded by the shared -soppu suffix: Yasopp preserves the Aesop-storyteller half of the name. Father carries the Aesop root; son carries uso + Aesop. The shared-suffix is the etymological tell that they are father-and-son before the in-story reveal at Ch. 25.
The payoff
Earliest known caller
Japanese readers identified the uso + Aesop pun immediately on Ch. 23 release (1998) — the bilingual pun is on-the-surface for native audiences. English-language One Piece communities surfaced the etymology via VIZ translator notes and SBS reader-Q&A archives (~mid-2000s). The Boy-Who-Cried-Wolf-inversion was a near-immediate fan reading by Ch. 25-41.
Why this matters
This is one of Oda’s earliest name-as-arc-prediction encodings — installed in Ch. 23 and continuously paid off across 1100+ chapters. The technique:
Encode a bilingual pun (Japanese surface + Western reference) into a katakana name.
Use the Western reference as the arc-shape predictor (Aesop fable → Boy-Who-Cried-Wolf-inversion).
Use the Japanese surface as the character-trait surface (uso = lie).
The character’s growth arc IS the gradual reconciliation of the two readings — the lie becomes a fable-with-moral-truth.
Generalization: when a One Piece character has a bilingual-pun katakana name, the non-Japanese reference is usually the arc-shape predictor, and the Japanese surface is the surface character trait. Sanji (san-ji = third-son, the Vinsmoke birth-order reveal) is a sibling case. Tashigi (snipe = flightless bird, the Kuina-succession reveal) is another. The Usopp case is the prototype for lie-becomes-truth name-encoding.