One Piece Drops a Massive Milestone Surprise Deep Under the Ocean’s Surface
One Piece has reached a historic moment. The long-running manga has now passed 600 million copies in circulation, according to publisher Shueisha and sales data previously shared by Oricon. The number confirms what fans already knew. The series is a global giant.
To celebrate the achievement, creator Eiichiro Oda did something unexpected. In a video released on social media, Oda is seen sitting at his desk in a dark room, carefully writing down the true secret of the One Piece treasure. This is the legendary prize that Monkey D. Luffy and many other pirates have been chasing since the story began.
After finishing the document, Oda seals it inside a small treasure chest. The chest is then locked inside a device shaped like a Log Pose. From there, it is handed to a team of divers and lowered deep into the ocean. The container disappears underwater, placed about 650 meters below the surface.
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— ONE PIECE スタッフ【公式】/ Official (@Eiichiro_Staff) March 3, 2026
それは、
物語が動き出した時から
決まっていた答え。
𝑻𝒉𝒆 𝒂𝒏𝒔𝒘𝒆𝒓
𝒉𝒂𝒔 𝒃𝒆𝒆𝒏 𝒅𝒆𝒕𝒆𝒓𝒎𝒊𝒏𝒆𝒅
𝒔𝒊𝒏𝒄𝒆 𝒕𝒉𝒆 𝒗𝒆𝒓𝒚 𝒃𝒆𝒈𝒊𝒏𝒏𝒊𝒏𝒈.
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#ONEPIECE
┗━━━━━━━━━━┛ pic.twitter.com/BoLydTm67Q
The project was carried out with help from the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and the Cross-ministerial Strategic Innovation Promotion Program (SIP). They assisted with both the deployment and the filming of the event. There are plans to retrieve the chest in the future, once the series officially reveals the truth about the One Piece.
Eiichiro Oda has written the secret behind the ONE PIECE Treasure on a piece of paper sunk to the bottom of the ocean.
— DiscussingFilm (@DiscussingFilm) March 3, 2026
Once the series ends, the truth will be revealed. pic.twitter.com/GZnLsdkgbK
The video also claims this is the first time Oda has ever written down the secret. Until now, he reportedly kept the ending only in his mind. That detail has caught a lot of attention, especially since the mystery of the One Piece treasure has been central to the story since it began in 1997 in Weekly Shonen Jump.
With over 600 million copies sold, One Piece is now considered the best-selling manga of all time. Some fans have compared its sales to Superman’s long comic history, though there is no clear data to make a direct comparison. Still, the sales milestone alone is massive and shows the series’ lasting power.
Technically, someone daring enough could try to dive down and recover the chest. But fans are hoping the secret stays safe until Oda chooses to reveal it in the story.
This was a smart and creative way to celebrate such a huge milestone. It keeps the mystery alive and shows how serious Oda is about protecting the ending. What do you think about hiding the biggest secret of One Piece at the bottom of the ocean? Share your thoughts in the comments.