Dangling noun — “a certain” village. The undefined modifier is a flag. Oda only ever uses “a certain X” when the X is identity-load-bearing and reserved for a later reveal.
Specific number — 100,000,000 berries. A number this specific must mean something specific is being bought. Round-but-large numbers (“a lot of money”) would not trigger the same pattern recognition.
Tangerine prop-tell (page 14) — “But I love money! And tangerines!” A character’s stated affection for a non-staple fruit is a tell; later paid off at Bell-mère’s tangerine grove in Cocoyasi.
The payoff
(Arlong Park arc — Cocoyasi Village, ransomed by Arlong for exactly 100,000,000 berries; the dangling village is Nami’s birthplace; the tangerine affection traces to Bell-mère’s grove.)
Earliest known caller
Called on first read by careful audiences — Oda flags it heavily through the
dangling-noun + specific-number + tangerine-prop-tell triple stack on the same
chapter.
Why this matters
This is the load-bearing seed for Nami’s entire East Blue character arc and
the emotional spine of the Arlong Park climax. A reader who notes the seed at
chapter 9 is positioned to predict the broad shape of Arlong’s reveal: there
is a village she needs to buy back from someone, and that someone is the
antagonist she’s actually working for. The “infiltration” beat with Buggy in
this very chapter is also a structural rehearsal of her actual relationship
with Arlong — pretending to serve a pirate while simultaneously stealing
from him to fund a hidden personal goal.
Ch. 70 partial-payoff
Three components of the seed-aggregate land in Ch. 70:
Village name: Coco Village (page 4: “It’s near Coco Village.”; page 14 caption: OUTSKIRTS OF COCO VILLAGE).
Tangerine grove location: at Nojiko’s house, the former Nami household (page 14 establishing-shot foregrounds tangerine trees).
Grower relation: Nojiko, the step-sister (page 14: “I’m Nojiko. I grow tangerines.”).
The 100M-berries-buyback amount component is still abstract; the Arlong tribute-tax mechanism is pending the flashback chapters.