#CROCUS
Crocus is a doctor and the caretaker of the whale Laboon as well as the overseer of the Twin Cape Lighthouse that guides ships coming down from Reverse Mountain into the Grand Line.
Though he was a lighthouse keeper for most of his life, he spent three years as a doctor serving as a part of Gol D. Roger’s crew, the only known crew to ever reach Laugh Tale, the end of the New World in the Grand Line.
On the final island, they found a treasure left behind 800 years ago by Joy Boy and learned the truth behind the Void Century, Ancient Weapons, and the meaning of the D.
#KOZUKI ODEN
Kozuki Oden was the daimyo of Kuri in Wano Country.
For 5 years of his life, Oden set out to sea and became a pirate, serving as the 2nd division commander of the Whitebeard Pirates and later becoming a member of the Roger Pirates. After finding Joy Boy’s treasure on Laugh Tale, Oden journeyed home and made it his goal to open Wano’s borders to the world by finally taking his father’s place as Shogun. However, he met opposition from his usurper Kurozumi Orochi and pirate Kaido, who executed him 20 years before the present.
As a descendant of the Kozuki Family, Oden inherited from his ancestors the knowledge and skill to read Poneglyphs and write its ancient language. He was a capable philologist, able to inscribe Roger’s message on the Shandorian Golden Belfry Bell in the same ancient language, as well as decipher all the Poneglyphs the Roger Pirates had found, particularly the Road Poneglyphs, which proved vital in the Roger Pirates’ success in locating and sailing to Laugh Tale.
#SCOPPER GABAN
Scopper Gasan was one of the Roger Pirates crew’s most major combatants, he was shown taking charge alongside Rayleigh during the crew’s last fight with the Whitebeard Pirates.
On the final island, he learned the truth behind the Void Century, Ancient Weapons, and the meaning of the D.
#SILVERS RAYLEIGH
Silvers Rayleigh, also known as the “Dark King”, is an extremely powerful and famous retired pirate who formerly served as the first mate of the legendary Roger Pirates, and known as the “Right Hand of the Pirate King”.
As indicated by him at Sabaody Archipelago, he discovered the true history at Raftel. Rayleigh offered to confide to Nico Robin the events of the Void Century, however, she refused the proposal since she wanted to journey with the crew to find the history for herself.
#GOL D. ROGER
Gol D. Roger was a legendary pirate who, as captain of the Roger Pirates, held the title of Pirate King and owned the legendary treasure known as One Piece.
With the information of every Road Poneglyph at hand, Roger and his crew ultimately made it to the elusive final island of the Grand Line. There, not only did they learn about the truth of the Void Century, the Ancient Weapons, and the Will of D., they also stumbled upon Joy Boy’s treasure. Roger and his crewmates reacted to this discovery with a burst of laughter. Roger professed his curiosity about Joy Boy, considering the circumstances behind this past figure as funny. Inspired by Joy Boy’s story, Roger bestowed the final island with the name of “Laugh Tale”.
#KAIDO
Chapter 1014 revealed that Kaido has knowledge of Joy Boy. What’s significant here is that Kaido is the first person to mention Joy Boy without having read the Poneglyphs. Probably he learned of Joy Boy through Rocks D. Xebec. According to Sengoku, Xebec dabbled in the world’s greatest taboos and there’s no greater taboo for the World Government than the true history. It is clearly shown that at some point in Kaido’s past, he had the belief that he himself was Joy Boy. In Chapter 1035, we see Kaido as young as we’ve ever seen him and it implies that he had already strong knowledge of Joy Boy even before meeting Alber/King. Anyway some event after that proved to him that he wasn’t Joy Boy. Probably ever since Kaido knew that he couldn’t be Joy Boy, he began to search for someone who can actually be Joy Boy.