Joy Boy was apparently a historic figure the lived back during the Void Century. He was first introduced in One Piece after Nico Robin read the Ryugu Poneglyph at the Sea Forest. Kozuki Oden believed Joy Boy would reappear 900 years after his initial appearance. Joy Boy is also responsible for the treasure known as One Piece. Not much is known about Joy Boy, however, the message he left on the Poneglyph suggests he had regretted failing to maintain his promise to Fish-Man Island. He attempted and failed to raise Noah, the massive arc known as the “ship of promise”. It’s not clear why Joy Boy wanted to raise the ship, but the civilians Fish-Man Island promised to keep the ship safe until it can be raised.
During the Fish-Man Island Arc, Vander Decken “threw” the entire ship at Shirahoshi using his Mato Mato no Mi abilities. I should note that Decken didn’t actually lift the ship but only needed to touch it to send it flying. The danger the ship presented forced Luffy to attempt to destroy it using his Elephant Gatling. Eventually Noah was stopped by a group of Sea Kings. Still Luffy damaged the ship. The Sea Kings took the ship to Sea Forest for repairs, stating that “the time for Noah’s mission was almost here”. At some point in his journey, Joy Boy became acquainted with Zunesha, a Naitamie-Norida Elephant, that walks continually with the island of Zou on it’s back.
Kaido defeats Luffy, again
Zunesha apparently is being punished for a past crime, sentenced to walk around without stopping. Miyagi speculates that “Zunesha is not walking aimlessly and may, in fact, be looking for a certain location”. Like Joy Boy there’s not much known about Zunesha. During the Wano Arc, Zunesha reached the waters of Wano Country. Through the “voice of all things“, Zunesha spoke to Momonosuke, telling him that it’s prepared “to fight under his command”. One Piece Chapter 1043 concludes the second fight between Kaido and Luffy, with the later losing again. Kaido is upset that his victory over Luffy came after the interference of the CP0 agent. After knocking Luffy unconscious, he asks the agent if he’s “prepared to face the consequences for his actions”. Kaido then strike him with his Hassaikai, as the CP0 agent does nothing.
Momonosuke can’t hear Luffy’s voice anymore and Kiado confirms that “Luffy is dead”. He wants Momonosuke to surrender, which the young warrior considers after Luffy’s defeat. While the Beasts Pirates cheer, the samurai and the rest of the allies despair. Of course Luffy isn’t dead but it’s concerning how he fails to defeat Kaido. The Yonko reveals how little he cares for the people of Wano, declaring them “slaves”, he only sees as sources of “cheap, free, and replaceable labor”. As Momonosuke considers giving up, Yamato challenges him. It might stop the war now but everyone would die as Kaido’s slaves. She reminds him of the decades of fighting that lead to this moment. Yamato would rather die than become a slave. Momonosuke is inspired by her words and decide to continue to fight. Suddenly, Zunesha speaks to Momonosuke, telling him it can hear the “Drums of Liberation”. Zunesha claims that this means “Joy Boy has returned,” as Luffy starts to smile with a weird substance covering him.