Ch. 45 page 14: Luffy wearing a sandwich-board sign reading “On Hiatus from Piracy / Free-Labor Chore Boy / MONKEY D. LUFFY”. The hero is reduced to his job title; the King-of-the-Pirates-aspirant wears his demotion-title.
Why this matters
The literal-label-on-Luffy gag is one of Oda’s recurring comedic-reduction devices. The hero’s identity is reduced to a job title he is performing temporarily — the gap between the title and the dream is the joke. Future instances:
Lucy in Dressrosa (gladiator-pseudonym)
Sanji’s Mr. Prince alias
The barrel-Luffy opening of the series (Ch. 1)
The cabin-boy-cooks-for-Krieg moment Ch. 47-48
The Ch. 45 sign is the first instance of the literal-text-label-as-comedic-reduction technique — a physical text artifact on the hero’s body that names his demotion.