The Biggest One Piece Mysteries Still Unsolved

What Is the Will of D.?

The initial D. appears in the names of the series' most significant characters. Monkey D. Luffy. Gol D. Roger. Marshall D. Teach. Portgas D. Ace. Jaguar D. Saul. The World Government fears the D. The Gorosei refers to it as "the Will of D." and treats its carriers as existential threats. But what it actually means has never been stated.

The most supported theory on Reddit is that D. stands for "Dawn." This connects to the Sun imagery throughout the series, the Dawn Pirates theory about Joy Boy's original crew, and the repeated references to a "new dawn" of the world. A closely related theory argues that the "D." are the enemies of the gods, which in One Piece's world means the Celestial Dragons who consider themselves divine.

Oda has been asked about the D. in interviews and has refused to answer, saying only that it "will be revealed naturally." The reveal is expected to be one of the final pieces of the puzzle, likely arriving at or near Laugh Tale.

Who Is Imu?

Imu sits on the Empty Throne, the seat in Mary Geoise that is supposed to be empty to symbolise that no single ruler controls the world. Imu is the true ruler of the World Government, above the Five Elders, above the Celestial Dragons. Imu's identity and nature are the single biggest geopolitical mystery in One Piece.

The dominant theories on Reddit are divided. One camp argues Imu is an immortal being from the Void Century, possibly one of the original 20 kings who founded the World Government, kept alive by the Op-Op Fruit's immortality surgery. Another camp argues Imu is a representation of the sea itself, connected to the Devil Fruit weakness to water. A third, more speculative theory posits that Imu is a surviving Lunarian or a being from the moon, tied to the ancient spacefaring civilisation glimpsed in Enel's cover story.

The Void Century

One hundred years of history, deliberately erased by the World Government. A Great Kingdom destroyed. Ancient Weapons created. The Poneglyphs scattered. Joy Boy made a promise he could not keep and apologised for it in a message carved into stone that has lasted 800 years.

The Void Century theory with the most community support, heavily discussed on r/OnePieceSpoilers, is that Joy Boy led a coalition of nations called the Dawn Pirates against the 20 Kingdoms, wielding the Ancient Weapons. He lost. The 20 Kingdoms became the Celestial Dragons and rewrote history. The One Piece is the key to undoing that rewrite, which is why the World Government has spent 800 years trying to prevent anyone from reaching Laugh Tale.

Joy Boy

Joy Boy was a pirate who lived during the Void Century. He made a promise to the people of Fishman Island. He failed to keep it. He left an apology on the Poneglyph at Fishman Island. He possessed the Nika fruit, the most ridiculous power in the world. The drums of liberation. Luffy is his successor, though whether that means reincarnation, inherited will, or something else entirely is one of the most debated questions in the community.

Zunesha, the elephant carrying the Mink tribe, recognised Luffy's heartbeat as the "drums of liberation," which it had not heard since Joy Boy. This single moment confirmed that Luffy and Joy Boy share something deeper than ideology. The exact nature of that connection is one of the final mysteries.

The Ancient Weapons

Three weapons capable of destroying the world: Pluton, Poseidon, and Uranus. We know Poseidon is Shirahoshi, the mermaid princess with the ability to command Sea Kings. We know Pluton is a warship that was built on Water 7 and its blueprints were passed down through generations of shipwrights until Franky burned them. Uranus remains completely unknown.

The strongest community theory about Uranus, debated on r/OnePiece, is that it is a sky-based weapon, completing the trio of sea, land, and sky. Some theories connect it to the moon civilisation from Enel's cover story. Others suggest it is the weapon Imu used to destroy the Lulusia Kingdom, and that it is already active in the present story.

Blackbeard's Mysteries

Marshall D. Teach is the most anomalous character in One Piece. He can wield two Devil Fruits, which is supposed to be impossible. He never sleeps. His body is "different," as Marco observed at Marineford. His Jolly Roger has three skulls. The theories about what Blackbeard actually is are among the most creative in the entire community.

The most popular theory is that Blackbeard has a split personality or multiple souls, possibly three, which explains the three skulls, the ability to hold multiple Devil Fruits, and his erratic behaviour. Another theory connects him to the Rocks Pirates and suggests his body was experimented on by the World Government. A third theory, more speculative, argues that he is a Buccaneer like Kuma, which would explain his unusual physique and his knowledge of Devil Fruit mechanics.

Which Theories Have the Strongest Evidence?

The Dawn theory for the Will of D. has the most textual support of any major One Piece mystery. The connection between D., Dawn, Joy Boy, and the Sun is reinforced across hundreds of chapters. Oda has been seeding this reveal for decades, and the community is confident it is correct.

The theories about Imu are harder to evaluate because Imu has appeared so rarely. The Void Century theories are robust but rely heavily on inference. The Blackbeard theories are the most speculative, and Oda has given the fewest clues. If Oda wanted to surprise the community, Blackbeard's secret is where he has the most room to do it.

One Piece is a story about mystery, but it is not a story that will leave its mysteries unresolved. Oda has known the answers since chapter one. The only question is how much longer he will make us wait.