Eiichiro Oda's One Piece follows the story of Monkey D. Luffy, a young boy who sets out to sea in the Great Pirate Era to find the treasure of the Pirate King – The One Piece. Over the years, One Piece has gradually become a legendary story and is also held in a different light compared to most manga.
A massive reason for that is the amount of care that Oda puts into the story, especially with his intricate details and incredible foreshadowing. Eiichiro Oda has, on countless occasions, shown that he's one of the very best at it and he simply loves to leave little clues for future events behind. While sometimes they blow up into events just a few months later, at other times, it takes a few years!
Updated on June 2, 2022, by Rei Penber: One Piece's author, Eiichiro Oda, is one of the most proficient writers when it comes to foreshadowing. Over the course of 1050 chapters, Oda has carefully placed important bits of information that later turn out to be major plot points. This list already includes 10 of the most incredible pieces of foreshadowing that the fans have seen in the story far, however, with a series as huge as One Piece, there is never a shortage of incredible foreshadowing instances. With that in mind, the list has been expanded with additional great moments of foreshadowing in One Piece.
14 The Yonko In The New World
The Yonko were first introduced in the story after the Enies Lobby arc through Garp. According to Koby, the Yonko rule the New World, and the one who eventually conquers the sea is the one crowned the Pirate King.
Fans got to see the silhouettes of the likes of Big Mom, Kaido, Shanks, and Whitebeard, all of which ended up playing an important role after the timeskip of the series. In the New World, Luffy fought against the supremacy of the Yonko and even took down Kaido to take an important step towards becoming the Pirate King, making it a brilliant piece of One Piece foreshadowing.
13 Monkey D. Garp's Introduction
Shortly before the series entered its Water 7 arc, fans got to meet Admiral Aokiji in the Long Ring Long Land arc. According to Aokiji, he was letting Luffy off because he owed his grandfather a huge debt. At this point, fans didn't know the relationship between Garp and Luffy, however, after the events of the Enies Lobby arc, Garp paid a visit to him personally.
Immediately after, fans got to know that Garp was indeed Luffy's grandfather. Although Garp let him off, he provided quite a lot of exposition on the likes of the Yonko and even Luffy's father, Monkey D. Dragon.
12 The Concept Of Haki
Haki was a power that was foreshadowed by Oda quite a long time before its proper introduction in One Piece. Shanks was seen using Conqueror's Haki to intimidate the Sea King that ate his arm. Although fans didn't know what this ability was at the time, it was later revealed to be the strongest power in the entire series.
Furthermore, during the Skypiea arc, fans got to see Observation Haki being foreshadowed and, once again, this ability then made a proper introduction nearly 300 chapters later when Rayleigh trained Luffy on Ruskaina.
11 The Power To Hurt Devil Fruit Users
Certain Devil Fruit users have incredible protection around their bodies that is offered by their ability. The likes of the Logias are all incredibly difficult to hit. At the same time, Luffy is also incredibly resistant to blunt attacks, thanks to his Devil Fruit ability.
During the Sabaody Archipelago arc, Oda introduced a strange ability capable of making contact with their real bodies and hurting them. After the Marineford arc, Oda introduced this power as Armament Haki and later built upon it as the story went on. Currently, it is one of the most incredible abilities in the One Piece world, once again showing how brilliant One Piece's foreshadowing is.
10 Laboon's Connection To Brook
Laboon is a whale who swam from the West Blue all the way to the Grand Line along with the Rumbar Pirates when he was a baby. Not letting him undertake a dangerous journey, Laboon stayed at the Twin Capes, hoping for the crew to, one day, return to him.
Sadly, the Rumbar Pirates all seemingly died. Despite that, Laboon continues to wait even though 50 years have passed already. In the Thriller Bark arc, Brook is revealed to be a surviving member of the Rumbar Pirates and he still plans to uphold his promise to Laboon.
9 Buggy's Great Connections
Buggy is quite a significant character in the world of One Piece even though he might not appear to be all that strong. He has great connections and this was actually foreshadowed quite early into the series. When Buggy lay low in the East Blue, he had a map of the Grand Line which was eventually stolen by Nami.
Buggy then aimed to "return to the Grand Line," implying that he'd already been there and calling his adventure "nostalgic." Later, he revealed he was one of the few who knew about Whitebeard's strength, once again, showing that he was a major figure in the past.
8 Jinbe The Shichibukai
Jinbe was once a member of the Shichibukai of the One Piece world and although he was introduced to the fans in the Impel Down arc, his first mention came long before that.
After Luffy defeated Don Krieg, he followed Zoro and Usopp to Arlong Park, and there, Arlong's connections to Jinbe were revealed for the very first time. It was revealed that Jinbe was, in fact, a Shichibukai like Mihawk and quite a strong one at that.
7 Shanks Vs Whitebeard
Shanks' talks against Whitebeard certainly gave the fans a clear idea of what was going to happen in the story. The conversation was mostly surrounding Blackbeard and how Ace shouldn't be chasing him because he's that powerful.
According to Shanks, the era would spiral into chaos if it were to happen and that's exactly what ended up happening as Ace was eventually captured, triggering the Paramount War.
6 Sabo's Death Ace's Tattoo
Sabo's death and existence is yet another incredible event that Eiichiro Oda had foreshadowed through the tattoo on Ace's left shoulder. Ace bore the "ASCE" tattoo in which the S was crossed out, implying the existence and the death of Sabo, one of Luffy and Ace's brothers.
Later on, in Luffy's flashback, Sabo was finally introduced to the fans and his journey with his brothers was shown to the full.
5 Sanji Being A Prince
Sanji's royal bloodline has been hinted at in the story on several occasions. To begin with, in the Alabasta arc, Sanji calls himself Mr. Prince, which is a clue to his former identity as a prince.
In Jaya, he mentions that he's actually from the North Blue and traveled to the East when he was a kid which, in hindsight, should've been impossible since you need to scale the Red Line to achieve that yet he somehow ended up in a different sea, which fans later found out was because of the Germa Kingdom.
4 Ace's Vivre Card
During the events of the Alabasta arc, Ace gave his Vivre Card to Luffy and told him that the paper will eventually bring the two together. After the Thriller Bark arc, Luffy noticed his Vivre Card was burning up, meaning Ace wasn't well.
In Amazon Lily, he was finally told that Ace was captured and that he would eventually be executed. The paper set Luffy up on the adventure to get to Ace and the seeds for this were planted long before the arc was even touched upon.
3 Kaido In The New World
Kaido is one of the Yonko of the Sea in the One Piece world and a fearsome pirate who is renowned as the "Strongest Creature In The World." In Thriller Bark, Moria mentions that he lost to Kaido in the New World long ago.
When he eventually also loses to Luffy, he warns him about the perils of the New World and that elites would eventually turn their eyes on him. At the same time, the arc also namedropped Wano Country, implying a connection between Kaido and Wano which later came to be true.
2 SMILEs In Sabaody Archipelago
The SMILE Devil Fruits became a huge plot point in One Piece following the Punk Hazard arc and it wasn't until the Wano Country arc that the dark truth about them was actually revealed to the fans.
Shockingly, SMILEs were actually mentioned by Donquixote Doflamingo in the Sabaody Archipelago arc before even the timeskip. Conversing with Disco on a snail, he called the age "the era of the SMILEs."
1 Time Travel
Perhaps one of the biggest and most shocking reveals in One Piece was that of time travel being involved with Kin'emon and Momonosuke. The hints for this were dropped all over the arcs before Wano. Momonosuke, despite being just 8, said that he met Roger long ago but he was a baby back then so his memory isn't that good.
Roger died 24 years ago, meaning Momonosuke meeting him should've been impossible. However, it was later revealed that Momonosuke came from 20 years in the past.