Tamatebox

Structural lore — what Oda has confirmed about this. Mysteries (unsolved questions) live in Vault/Threads/; this is what the world IS.

What we know

• Ch. 626 pp. 2-3: A special treasure box said to be hidden inside Ryugu Castle that “has the power to make anybody age” — described by Vander Decken IX as able to turn “a tiny little kid… into a sexy young woman.”
• Ch. 626: Vander Decken IX covets the box; his entire scheme to marry Princess Shirahoshi is partly a means to access the otherwise-impenetrable castle and reach it.
• Ch. 648 p. 8: After the battle, the Ryugu Palace treasure chamber is found ransacked; the Tamatebox holds “not a coin”. The recovered kidnapped mermaids “remember the kidnapper’s face well.” (Whether the box itself was taken/tampered is left open — Chekhov prop-tell; culprit unseen on-page.) See The Tamatebox Was Emptied And The Treasury Ransacked By An Unseen Thief.
• Ch. 650 pp. 14-16 — The legendary pills stored inside the Tamate Box were the Energy Steroids; their contents vanished ten years ago, stolen by Hody Jones. Confirms the box’s age-altering property is plot-load-bearing: the drug has aged Hody’s crew into old men. The minister suspects it was “a dangerous drug labeled a ‘treasure’ to keep it out of the people’s hands.” (Distinct from the giant golden Tamatebako prop; this is the box that once held the aging pills.) See Tamatebox Treasure That Makes People Age Decken Wedding Plot.
• Ch. 652 pp. 5-8 — The Tamatebox was secretly armed with a bomb ten years ago when it was found empty — it will explode when opened. The Minister of the Right (keyholder to the treasure vault and the box) fears that, since the box was handed to Big Mom along with Fish-Man Island’s tribute treasure, opening it would trigger a blast “seen as a direct assault from Luffy’s group” — and Luffy has just provoked her by phone. Adds an explosive property to the previously-known age-altering one. See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute.
• Ch. 653 p. 5: As the Straw Hats depart, King Neptune and his ministers reveal the box was sent up to Big Mom with its decade-old bomb still inside and fret it will detonate in the Yonko’s palace (“you planted this bomb a decade ago, yes?”; “one of the Four Emperors has it in for us!”). The bomb-armed box has now physically left the island in a Yonko’s possession, fuse unresolved. See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute, Four Emperors (Yonko).
• Ch. 847 pp. 11-12: Big Mom reveals she still holds the Tamate Box — Fish-Man Island’s hereditary national treasure, given to her by King Neptune as tribute/“contrition” alongside the kingdom’s treasure — and that she plans to open it publicly at the tea party “in front of everyone.” The bomb-armed box (seeded @0652–0653) is now staged for a public opening in the Yonko’s own hall; the fuse remains unresolved. See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute.
• Ch. 848 pp. 4-5: Big Mom keeps the Tamate Box in her treasure repository (the Chambre de Treasure) and lists it as a prize of tomorrow’s wedding — “I’ll have Germa’s power and the Tamate Box” (p. 4) — then reacts with alarm to the Brook/Pedro infiltration: “They better not be after my Tamate Box!!!” (p. 5). The staged public-opening fuse (seeded @0652–0653, @0847) remains unresolved. (canonical_chapters += 0848.) See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute.
• Ch. 869 pp. 13-14: During the wedding chaos a Big Mom Pirate swipes the giant Tamate Box to “switch out the contents,” cracks it open, and it slips loose — the bomb-rigged tribute box is now loose and unaccounted-for inside Whole Cake Chateau, re-positioned for a later detonation. The recurring “who’s been at the box” prop-tell stays alive. (canonical_chapters += 0869.) See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute, The Tamatebox Was Emptied And The Treasury Ransacked By An Unseen Thief.
• Ch. 871 pp. 4-6, 16: The Tamate Box, dislodged in the wedding chaos, hangs precariously on Whole Cake Chateau and tumbles further. The underworld figure Du Feld lunges for its “Treasure of the Deep” and is shot down by Stussy (CP0), who declares the World Government will be claiming the box. The bomb-rigged prop is now physically loose and in play around Big Mom’s stronghold — detonation still forward. (canonical_chapters += 0871; related_topics += Stussy, Du Feld.) See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute, The Tamatebox Was Emptied And The Treasury Ransacked By An Unseen Thief.
• Ch. 861 pp. 6-7: The Tamate Box is presented to Big Mom among the wedding-gift treasure chests at the tea party — described as “the chest of legend,” passed down through “the dynasty of the underwater kings,” which “somehow… let it slip from Neptune’s grasp.” Morgans (WEJ) is said to have heard of it first. Big Mom declares she will open it publicly at the grand banquet after Pudding’s ceremony “with the other presents for all to see.” The bomb-armed box (seeded @0652-0653, staged @0847-0848) now has a stated public opening time/place; the fuse remains unresolved. (canonical_chapters += 0861; related_topics += Morgans.) See The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute.

Chronology / structure

A planted prop (Chekhov’s box). Named for and modeled on the 玉手箱 tamatebako (‘jewel-hand / precious box’) of the Urashima Tarō legend — the box the dragon-palace princess Otohime gives Urashima at Ryūgū-jō, which releases his stored years as white smoke and ages him 300 years when he opens it. The fairy-tale overlay is reinforced by the Ryugu (“dragon palace”) Kingdom setting and Queen Otohime’s name (Oto-hime, the dragon-palace princess of that same legend). Etymology resolved — see the frontmatter etymology block (sources: One Piece Wiki — Tamatebako, Wikipedia — Urashima Tarō).

Open questions about this topic

• Ancient Weapons — (tangential) the FMI Poseidon vector this arc orbits; the Tamate Box’s age-altering power is set up to matter later — payoff forward of this window.
• Who ransacked the treasury and emptied the Tamatebox during the chaos, and to what end? (@0648 — culprit unseen on-page.)

Cross-links

• Characters connected: Vander Decken IX, Shirahoshi
• Location: Ryugu Castle
• Foreshadowing seeds about this topic: Tamatebox Treasure That Makes People Age Decken Wedding Plot, The Tamatebox Is Bomb-Armed And Handed To Big Mom As Tribute