Joy Boy is a title of great historical significance. It remains unclear as to how one exactly obtains this title, but people have looked to individuals with world-changing aspirations as its next bearer.
So far, two people with the title "Joy Boy" are known to have existed. The first and most well-known one was an extremely relevant figure in the Void Century who played an important role in the history of Fish-Man Island and left behind a certain item of unimaginable value on the last island of the Grand Line. He was first mentioned on the Ryugu Poneglyph read by Nico Robin while at the Sea Forest.
Based on the historical recordings of this Joy Boy left on the Poneglyphs, it was believed that Joy Boy would return around 800 years after the Void Century. After Monkey D. Luffy awakened his Devil Fruit, the Hito Hito no Mi, Model: Nika, and his heartbeat took on the sound of the "Drums of Liberation", Zunesha stated that Joy Boy had returned.
First Joy Boy
Around 900 years ago, the residents of Fish-Man Island made a promise to a great man known as Joy Boy. He attempted to raise Noah with Poseidon's aid, but he broke his promise to Fish-Man Island due to an unknown reason.
The original Joy Boy left messages regarding his return 800 years later. One of those messages was to Fish-Man Island and to Poseidon, apologizing for breaking his promise, and promising that someone would fulfill it in the future. Another message was left at the unnamed island, claiming that he would return in 800 years' time.
When the Roger Pirates conquered the Grand Line by reaching the then unnamed island, they read the message and learned the true history of the world but decided to leave it as is, as they were too early. Roger declared that he wished the two could have lived during the same period upon learning the true history on Laugh Tale.
Fish-Man Island's half of the promise was almost broken during the events of the Fish-Man Island Arc, when Monkey D. Luffy was asked to protect the island no matter what the cost, even if it meant that Noah had to be destroyed in the process. Before Luffy could destroy the ship completely, Noah's fall was stopped by a group of Sea Kings that were summoned unknowingly by Shirahoshi, thus saving Fish-Man Island and maintaining the nation's promise to Joy Boy. However, the ship was still heavily damaged. The Sea Kings then took the ship to the Sea Forest, where they planned to fix it.
|— Kaidou about Luffy|
During the Roger Pirates' journey, after Kozuki Oden joined, they traveled to Fish-Man Island and on their way, both Roger and Oden heard the Sea Kings talk about the birth of someone who will lead them in 25 years along with the new Poseidon. After the crew's discovery on Laugh Tale, Oden returned to his home in Wano Country, which also had a connection to Joy Boy, and made plans to open up the enclosed land in preparations to Joy Boy's return. However his efforts were foiled by the then shogun Kurozumi Orochi and pirate Kaidou, and he was then killed by the latter, so he left the task to his retainers.
At an unknown point in time, Kaidou learned about Joy Boy and has been searching for the next one for an unknown reason. King, a member of the Beasts Pirates and a lunarian, seemingly believed that Kaidou could have become Joy Boy and change the world, although he eventually came to dismiss the figure as a mere legend. Sometime after Oden's death, Yamato, Kaidou's child and an admirer of Oden, took up Oden's name and after learning the truth from Oden's journal, worked to fulfill his dream.
After Monkey D. Luffy was defeated by Kaidou on the Skull Dome rooftop, Zunesha proclaimed that it can hear the "Drums of Liberation" (解放のドラム Kaihō no Doramu?) and that Joy Boy has returned. Luffy then began to regain his consciousness and grinned, awakening his Devil Fruit and transforming into his Gear 5 form for the first time.
- The first Joy Boy made a promise with the residents of Fish-Man Island 900 years ago, but since the Poneglyphs were invented by the Kozuki Family 800 years ago, his letter of apology was inscribed at least a century later.
- The Encyclopedia of Things That Never Were by Michael Page and Robert Ingpen describes Joyboy as a figure from Caribbean folklore associated with humans' need to dance, sing, and celebrate. Joyboy has been probably brought to the Caribbean islands along with West African slaves. He smiles at all the world's problems and cures the ills of humanity by playing his drum. Whoever hears his music is forced to dance and sing until they cast off their black veil of despair.