Everyone knows that the high seas are full of mystery, and nowhere is this truer than in Eiichiro Oda’s legendary manga and anime franchise, One Piece. Comfortably and consistently the most popular manga in its native Japan, the adventures of Straw Hat Luffy have racked up nearly 800 anime episodes and over 850 manga chapters since debuting in 1997.
It has become one of the best-selling series in history. Although initially struggling to find a Western audience thanks to a truly awful adaptation, advances in technology have exposed One Piece to a global audience and the property is now an international franchise.
Apart from the glut of amazingly designed and well-developed characters and the unending stream of exciting, gripping story lines, Shonen Jump's One Piece is famous for its mysteries. Considering the fact that the series has been running for twenty years, it’s surprising how many questions still remain unanswered on the tides of the Grand Line.
Let's explore the most significant mysteries yet to be fully addressed in the One Piece universe, from huge characters fans have barely seen to story elements that have been hinted at but are yet to come to the fore.
Here are the 15 Biggest Mysteries and Questions in One Piece.
15 Who is The New Third Admiral?
After the Paramount War between the Whitebeard Pirates and the Marines, a shake-up at the top of the sea-faring command chain was in order, as Fleet Admiral Sengoku stepped down, Akainu took his place, and Aokiji resigned.
With only Kizaru remaining in his role as Admiral, two replacements were needed and the first of these was revealed in the Dressrosa arc: the fair but fearsome Admiral Fujitora.
This leaves one new powerful figure at the top of the Marine hierarchy who fans have yet to see. All that is known about this mysterious person is that their codename is Ryokugyu, which translates to “Green Bull.”
There is currently no available information regarding this character’s power, Devil Fruit ability, or how they came to be an Admiral in the first place, but it’s certain that this new figure will come to prominence in a future storyline.
14 Why is Kaido Immortal?
The Yonko Kaido has been built up for an awfully long time and seems destined to face off with Monkey D. Luffy sooner rather than later. Although much of his power and abilities remain hidden, Oda has dropped several teases, the most intriguing being Kaido’s supposed inability to die.
In a brief scene, Kaido is seen attempting to commit suicide, seemingly for the umpteenth time. Once again, he fails and a short flashback montage claims that the pirate has been captured many times by the Marines, yet they have failed to execute him on each occasion.
This begs a whole host of questions and theories as to how Kaido gained his apparent immortality. Is he just incredibly durable? Is it a Devil Fruit power? Did someone make him immortal using the Ope Ope Fruit?
The questions are many and the answers are few, but the story is slowly creeping toward the eventual clash between Luffy and the Beast where all should be revealed.
13 What's the Full Potential Behind Devil Fruit Awakenings?
It has been clear for some time that there are different levels to a person’s ability to control their Devil Fruit, a concept perfectly demonstrated by Luffy’s Gear Second, Third, and Fourth transformations. However, in the fight between Luffy and Doflamingo, the Warlord revealed that Devil Fruits could be "awakened" to unleash an entirely new grade of power.
The only awakening showcased fully so far has been Doflamingo’s own (although Big Mom’s may be incoming shortly) and the ability seems to allow Doffy to transfer the power of strings to his surroundings.
Aside from the question of how this level is attained in the first place, the real mystery is what each Devil Fruit-using character’s new power will be. Will Luffy be able to turn buildings and objects into rubber? Will Chopper gain a new type of transformation? The possibilities are both intriguing and endless.
12 Who is Joy Boy?
One character who remains a mystery, yet still appears to be a significant figure in the overall story, is Joy Boy. Currently assumed dead (though you can never rule anything out in One Piece), this person was first mentioned during the Fishman Island arc, and seems to be an important factor in the relations between the Fishmen and the surface-dwelling humans.
Joyboy was much loved by the race of Fishmen and the underwater islanders promised to protect the ancient ship, Noah, for him. Upset by his inability to raise the Noah himself, Joy Boy leaves a message of apology to Fishman Island etched onto a Poneglyph, which is an impressive feat in itself since the stones are not easily tampered with.
With so little information available, this mystery is likely to unravel near the series’ endgame.
11 How Powerful Are The Gorosei?
Restricted to only a handful of fleeting appearances, the five old men who rule the world of One Piece are one of the story’s huge enigmas. Everything from their names to their backgrounds are shrouded in mystery and, given that they’re sitting at the top of the World Government, it also has to be assumed that this group possess great power in some form or another.
Their existence is no doubt inextricably linked to some of the other mysteries, and the five men will also surely have huge roles to play in the Earth-shattering event that has been hinted at occurring sometime in the future.
One popular theory among fans was that the youngest-looking member of the Gorosei was actually Sanji’s father, however this has recently been debunked, indicating just how little fans know about this supremely powerful group.
10 What is Shanks’ True Power?
"Red Hair" Shanks may be one of the most popular characters in the entire series but, even as One Piece creeps towards its one thousandth chapter, fans have yet to see Shanks and his crew properly fight. Sure, they’ve squabbled with a few bandits, and Shanks has displayed his Conqueror’s Haki on several occasions, but the pirate’s status as a Yonko guarantees he’s capable of much more.
This sentiment was more or less confirmed when the Red Hair Pirates appeared in the Paramount War, where their presence effectively ended the conflict, with both the Marines and the Blackbeard Pirates making it clear they wanted no part of Shanks and his pals.
In all likelihood, Shanks’ true power won’t be revealed until much later in the series, either in a major future conflict or in the proposed "fight between pirates" that Shanks and Luffy promised each other when the latter was just a child.
9 What Happened to Luffy’s Family?
There are a few salient gaps that require filling when it comes to the background of our happy-go-lucky protagonist, Luffy. Most importantly, fans are desperate to see Luffy’s mother and the situation surrounding his birth.
For instance, why did Dragon leave his son? Does he have any other blood relatives, such as siblings or aunts and uncles?
Luffy himself has demonstrated on numerous occasions that he couldn’t care less about his heritage and he considers his only true family to be Ace, Sabo, and his crew. As such, information about the character’s background is going to have to come from an outside source-- possibly Garp or potentially an entirely new character who is a member of Luffy’s immediate family.
If such knowledge did come to light, it would be a groundbreaking moment in the series.
8 How is Blackbeard Wielding Two Devil Fruits?
At the climax of the Paramount War, Blackbeard surprised everyone by taking a beaten, weakened Whitebeard behind a cover, and doing something unspeakable to him. The result was that only Blackbeard emerged alive, and he did so wielding both his own Yami Yami Fruit and Whitebeard’s famous Gura Gura Fruit.
This completely goes against every established rule of Devil Fruits in the One Piece series, as it has been stated on several occasions that if a Devil Fruit user eats a second Fruit, they will surely die.
There are several possible explanations for this anomaly, ranging from a special feature of the Darkness Fruit, to an ornate blade that the Blackbeard Pirates have been seen to possess. Another potential answer was hinted at in a recent manga chapter, which revealed that Big Mom gained her Devil Fruit power by eating its original user. Perhaps this method circumvents the usual two-Fruit rule.
7 What Mysteries Surround the "Voice of All Things"?
One of the more recent additions to the One Piece canon is the mysterious "Voice of all Things." This ominous sounding title refers to the ability to communicate with, or hear, the voices of animals and objects, and is possessed by the likes of Monkey D. Luffy and Gol D. Roger, among a very select few others.
Like the Conqueror’s Haki, this ability seems to be something a person is born with and, although they can become more adept at using it, it’s not possible to develop the power if you don’t have it already within you.
Oda hasn’t exactly been shy in drawing parallels between Luffy and Roger, but the "Voice of all Things" is perhaps the clearest signal yet that these two share a very similar path. One Piece has barely begun to scratch the surface of this mystery, and it will likely develop slowly as the Straw Hats near Raftel.
6 What is the Uranus Weapon?
In the Water 7 arc, the existence of three unimaginably powerful weapons was revealed, two of which have already appeared in the series in some form. The great warship Pluton was the main goal of both Crocodile and Spandam and, although Franky managed to destroy the blueprints, the original ship may still appear in the series.
The second weapon, Poseidon, appeared in the Fishman Island arc, and was revealed to be the shy and unassuming mermaid, Shirahoshi, who has the ability to control Sea Kings.
The final weapon that still remains a mystery in One Piece is the Uranus Weapon (stop laughing!). Extremely little is known about this ancient relic. It’s difficult to predict exactly how important the three weapons will be in the arcs to come, but fans will surely find out what Uranus is, even if they don’t get to see it in action.
5 What Is Monkey D. Dragon's Story?
Arguably the only central character more enigmatic than Luffy’s surrogate father, "Red Hair" Shanks, is his actual father, Monkey D. Dragon. There’s plenty about Luffy and Dragon’s relationship and family that has yet to be revealed, but there’s also a lot that needs to be explored concerning Dragon’s personal and professional life.
For example, what is his Devil Fruit power exactly? The incident in Logue Town strongly suggests something to do with weather control, but other than that, fans are in the dark. More importantly, what motivated Dragon to become the leader of the Revolution Army?
Going head-on against the World Government and Marines isn’t something a person does lightly, and there is surely an emotional and significant story behind this decision. Some have even speculated that Dragon was originally a Marine Admiral, which would be a seismic revelation.
4 Does the All Blue Exist?
Each member of the Straw Hats has their own personal ambitions, in addition to their goals of travelling the world together and helping Luffy become the Pirate King. Sanji’s dream is to discover the fabled sea, the All Blue.
Supposedly, All Blue has every type of fish imaginable in its waters which, for a chef like Sanji, is an absolute dream. Many doubt that the place even exists, and the Curly-Browed one has often been mocked due to his unfaltering belief that the All Blue is real.
Assuming it does exist, All Blue is likely to be located somewhere near Raftel, or in a location shown in the Road Poneglyphs, as this would explain why it has remained elusive for so long.
As a fan favorite character, many readers and viewers would love to see Sanji’s dream realized, even if the chef himself wouldn’t hesitate to trade finding the All Blue for an attractive girlfriend.
3 What Happened During the Void Century?
No one has any idea what happened in the one hundred years preceding the World Government's rise to power. This is mighty suspicious, and it doesn’t take much to figure out that the authorities may have something to hide about how exactly they managed to gain control of the world, particularly considering their actions at Robin’s homeland of Ohara.
The events of the Void Century are chronicled in Poneglyph format and, given that Robin is one of the few people able to read the stones, the Straw Hats are in prime position to uncover the secrets of this gap in history before anyone else.
Of all the mysteries on this list, the uncovering of the Void Century is likely to have the most sizeable and far-reaching ramifications in the One Piece universe and may well spark a war the size of which has never been seen.
2 What is the Significance Behind the Will Of D?
This mystery is intrinsically woven around main character and protagonist Monkey D. Luffy, as well as a variety of other characters burdened with "D." as a middle name, such as Trafalgar Law and Blackbeard.
The Will of the D. (again, stop laughing!) has been hinted at in One Piece for many years and some information has indeed been revealed on the topic. It is known that the D. was a tribe from long ago that was widely considered to be the natural enemy of the Celestial Dragons.
This is more or less where the knowledge ends, but the Will of the D. mystery is almost certainly linked to other questions, such as the mystery of the Void Century, Dragon, and the Gorosei, so when answers do eventually come, they may all come at once.
1 What is the One Piece?
Naturally, the biggest mystery in One Piece is the very item the series is named after. The most significant question, of course, is what exactly the One Piece is.
Surely any amount of gold or jewels could never justify such a long and dangerous journey, and Oda has also reassured fans that he won’t be pulling the "real treasure is the adventure you had to get here" trick, thankfully.
This then means that the precise nature of this grand treasure is a complete unknown. It could be a vital piece of information regarding the world or its history, it could be a person that Roger held dear, or it could be an item of terrible power that Roger hid from the world. It might even be a plastic first place medal with a skull and crossbones on it.
Are there any One Piece mysteries we've missed? Leave your own theories and speculation in the comments section!