Eiichiro Oda has kept One Piece fans guessing for years by revealing that Joy Boy was defeated by the alliance of 20 kingdoms around 800 years ago. These kingdoms were ruled by 20 monarchs who joined forces to wage war against the Ancient Kingdom during the Void Century and are widely believed to have played a key role in Joy Boy’s downfall. While most fans believe Imu emerged victorious in the final battle, one popular theory suggests that Joy Boy may have deliberately accepted defeat as part of a much larger plan.
As Eiichiro Oda has confirmed, One Piece is now in its final saga. That means fans may finally get answers to some of the series biggest mysteries, including what really happened to Joy Boy and the downfall of Ancient Civilization.
If this theory turns out to be true, it could reveal one of Eiichiro Oda’s biggest twists in One Piece history.
Who was Joy Boy?
Joy Boy was a legendary figure from the Great Kingdom, born around 900 years ago at the start of the Void Century. Often called the first pirate in history, he fought against the alliance of twenty kingdoms that would later become the World Government.
He held the Human-Human Fruit, Model: Nika, a Mythical Zoan Devil Fruit that let him transform into the Sun God Nika, the same fruit Luffy carries today.
During the Void Century, Joy Boy made a promise to Poseidon on Fish-Man Island involving the giant ship Noah, agreeing to help fulfill its purpose. For reasons still unknown, he couldn’t keep that promise. Before he died, he left an apology on a Poneglyph, and ever since, the people of Fish-Man Island have protected Noah, waiting for the day his promise is finally honored.
Episode 1153 gave fans their first real look at Joy Boy, and it overturned a popular theory. Rather than being a giant, his silhouette closely resembled Luffy’s, leaving fans to question whether the giant frozen straw hat in Imu’s possession ever belonged to Joy Boy at all.
This is where the mystery starts. Oda still hasn’t shown the actual confrontation between Joy Boy and Imu. We know Joy Boy fought in the Void Century war, and we know Imu hasn’t forgotten him, but the manga has never revealed how Joy Boy was defeated or what role Imu played in that final battle.
That gap has fueled two main fan theories. One says it was a clean, total loss, pointing to Imu’s immortality, control over the Five Elders, and access to powerful weapons. The other says the defeat was tactical, not final, citing the knotted Haki built to detonate centuries later, the Poneglyphs spread worldwide, and the Will of D. as evidence that Joy Boy was playing a longer game.
What really happened between them remains one of One Piece’s biggest unanswered questions.
Why Imu Still Fears Joy Boy
More than 800 years have passed, yet Joy Boy still seems to have a lasting impact on Imu. That alone suggests there is much more to their history than readers currently know.
One of the biggest moments came during the Egghead Arc. When Emet released the stored Joy Boy’s Haki on Egghead Island, it forced the Five Elders out of their transformed states, sent several of them back to Mary Geoise, and knocked out many Marines, including Vice Admirals.
Imu also sensed the burst of Haki from Mary Geoise and reacted immediately. While the manga does not explain exactly what Imu was feeling, the scene has led many fans to believe that Joy Boy’s power still unsettles Imu even after 800 years.
This has become one of the strongest arguments behind the theory that Joy Boy’s defeat may not have been as straightforward as it first appeared. If true, it could mean Joy Boy left behind a plan that continued long after the Void Century ended. However, Eiichiro Oda has not yet confirmed what really happened between Joy Boy and Imu, so this remains a fan theory rather than established canon.
What We Still Don’t Know About the Void Century War
Despite having all the clues in front, one major piece of the puzzle is still missing: the final confrontation between Joy Boy and Imu.
Readers know that Joy Boy fought against the alliance of 20 kingdoms during the Void Century. That war changed the course of history in One Piece. However, Eiichiro Oda has never shown what actually happened between Joy Boy and Imu.
The manga has not revealed whether they fought one-on-one, how the battle unfolded, or how Joy Boy was ultimately defeated. Whether Imu won through superior strength, strategy, betrayal, or some other unknown factor remains a mystery.
This appears to be an intentional decision by Oda. Throughout One Piece, he has carefully held back key details until the right moment, and the truth behind Joy Boy and Imu’s final encounter is one of the series’ biggest unanswered questions.
Because the manga has not provided a definitive answer, fans continue to build theories using the clues that have been revealed so far, including Imu’s reaction to Joy Boy, the hidden Conqueror’s Haki stored by Joy Boy, and the mystery of the Poneglyphs. Until Oda reveals the full story, every explanation remains a fan theory rather than confirmed canon.
Why Some Fans Believe Joy Boy Planned His Defeat
This theory gained attention after YouTuber BBF discussed it in one of his videos. He argued that the Ancient Kingdom was far more advanced than the world seen in One Piece today. According to the theory, it possessed highly advanced technology and powerful Ancient Weapons like Pluton and Uranus. This suggests the alliance of 20 kingdoms needed more than military strength alone to defeat an advanced civilization.
Fans may remember Gol D. Roger’s reaction after reaching Laugh Tale and discovering the One Piece. Instead of mourning Joy Boy’s fate, Roger laughed and said he wished he had lived during his era. This theory suggests that the reaction hints the Ancient Kingdom’s story was more complex than a simple defeat. If Joy Boy had merely lost the war, he argues, Roger’s response might have been very different.
The Egghead Arc adds another piece to the puzzle. Professor Clover was killed for researching the Void Century, and Dr. Vegapunk also became a target after revealing hidden truths about the world’s history. Together, these events suggest the World Government is still determined to hide what happened 800 years ago.
Another clue comes from One Piece Chapter 968. The Sea Kings speak of a prophecy involving two rulers who must be born in the same era to guide the world toward a better future. According to the prophecy, one ruler would come from the land and the other from the sea. Many fans believe Joy Boy was the ruler from the land. However, Poseidon, the ruler of the sea, had not yet been born during Joy Boy’s time, which may explain why his plan could not be completed.
Joy Boy also left an apology on a Poneglyph at Fish-Man Island for failing to keep his promise to Poseidon. Notably, the apology was for breaking that promise, not for losing the war. He believes this is an important distinction. They argue that Joy Boy may have been preparing for a plan that would only be completed centuries later.
There are other details that fans point to as well. Alongside the Kozuki Clan, Joy Boy is believed to have helped create the Poneglyphs so that important information could survive through the centuries. Wano’s closed borders also appear to have been part of a long-term plan, protecting key secrets until the right time.
Even Zunesha and Emet seem to fit this pattern. Zunesha has wandered the seas for centuries while waiting for the return of Joy Boy. Emet remained inactive until the events of the Egghead Arc, when he finally released Joy Boy’s stored Conqueror’s Haki. To many fans, these events suggest that several pieces of Joy Boy’s plan were meant to unfold hundreds of years after the Void Century.
Conclusion:
Joy Boy may not have lost to Imu. Instead, they believe he accepted defeat as part of a much larger strategy that would only bear fruit centuries later. However, this remains a fan theory. Eiichiro Oda has not yet revealed what truly happened between Joy Boy and Imu or how the Void Century war came to an end.
| Publisher | Shueisha |
|---|---|
| Author | Eiichiro Oda |
