Before their encounter of Fishman Island, to which is located under the sea, for the underwater passage way to the New World, Is the Straw Hat Pirates ultimate goal. To pass through there and mark the start of their journey in the New World. However, instead of finding the long-sought after destination, the Straw Hats encounter another obstacle: the Red Line, the continent that encircles the Prime Meridian of the world. Having originally entered the Grand Line at Reverse Mountain on the other side of the Red Line, this means that the crew has traveled half-way around the Grand Line. With the continent blocking access into the New World, Luffy's dream of acquiring the title Pirate King is put on hold.
Therefore, the presence of the Red Line poses many problems to the Straw Hats. For one thing, the extremely tall Red Line looks impassable, Also, their exact location is close to many of the crucial government landmarks, including the holy land of Mariejois and Marine Headquarters. Since the only way to get to the new world is the Red Line, and the government forbidding pirates to enter, the Straw hats have to find another way through. This is where fishman island comes into play. Having found out about the mythical island through Keimi, a mermaid from fishman island, and her talking starfish, Pappug. They were recused from almost being eaten by a sea king (a giant fish), to thank the straw hats, Keimi suggests takoyaki from Hatchan's Takoyaki 8 stand. Therefor calling Hatchan. Although after the attempt someone else picks up instead of Hatchan. Turns out that the Macro Pirates have caught Hatchan, intending to sell him into slavery. Keimi wishes to save him and Luffy, the captain of the strawhats, agrees to do so.
Keimi uses her ability to be able to speak with fish and navigates the ship towards Grove 44 of the Sabaody Archipelago, having been told that Hatchan is being held at the base of the Flying Fish Riders, which lies on this route. Before they arrive, they are attacked by the Flying Fish Riders, who after a brief battle return to their base to report back to their leader, Duval, an extremely tall man in an iron mask. The character Hatchan is soon revealed to be apart of Nami's past, a sad hurtful past, Hatchan having use to be working with Arlong, an evil fishman that took over Nami's hometown until Luffy saves it, she is cautious about saving Hatchan. But for their new friends, Keimi and Pappug, they are willing to save him, although Hatchan is still not yet forgiven for what happened all those years ago.
After their victorious battle, the story then moves ahead with the Sunny (strawhats ship) back at sea and The Straw Hats are heading for Sabaody now while they have a takoyaki party with Hatchan's cooking. It is then that Duval shows up again and expresses his gratitude for the change in his looks (and gets into fits about his own beauty), then gives the crew his number, saying if they need anything to just call him up before he and his gang (now renamed the Rosy Life Riders) depart.
After arriving at Sabaody, Hatchan then says they'll need a special coating to make sure the ship gets to Fishman island all right. Hatchan promises to take them to a mechanic he would "bet his life on", but they have to promise not to oppose the World Nobles (the decedents of the ones who created the World government), they are people who are allowed to live in Mariejois and are sometimes seen walking around Sabaody, even if someone was to be killed before their very eyes. A little while after that some of the straw hats decide to venture about and search for the mechanic to coat their ship, Usopp, Franky and Sanji stay on the Sunny to fix the damages to the ship (or in Sanji's case to look after the treasure for Nami), Zoro off on his own, most likely getting lost, due to his terrible sense of direction, And Luffy, Nami, Chopper, Robin and Brook tour the island with Hatchan, Keimi and Pappug acting as guides. Hatchan warning them not to draw attention to themselves as even though pirates walk freely on the island so do Marines and bounty hunters, plus if they are captured and sold as slaves the law will not help them. He also mentions to treat Keimi and himself as regular people calming it'll be easier for them (even bandaging the mark on his forehead, something Luffy notices).Nami and Robin soon spot shopping malls and such, therefore departing from the group. However Robin cannot but notice Keimi acting reserved since they've gotten to the island.
No sooner then they leave the group, a pirate captain runs through the town, begging the citizens to removes a collar from his neck. He pleas that he has given up on the new world and just wants to leave, even claiming he has a wife and child, the latter whose never even seen him since he was a baby. Hatchan however tells the group not to help him as he a slave of the World Nobles. After mentioning this fact, the collar activates and blows up the captain though he surprisingly survives still feebly begging to leave. Two nobles, Roswald he and his daughter, Shalulia, show up afterwards causing everyone to bow as they pass. After a dog urinates on the noble Roswald, being carried on a chair by a slave in his back, Shalulia kicks him before shooting him with a pistol, Luffy nearly attacks them after seeing this but Hatchan stops him. Roswald and she then causally walk away talking buying another slave.
The group then talks about the oddity of it since the pirate looked strong enough to deal with both nobles. But Pappug comments that wounding one would make the offender the target of one the admirals. When asked what gives the nobles such special treatment, the starfish tells them that they are the descendants of the ones that created the World Government, and due to this they have become abusive with their influence.
Despite having witnessed the cruelty of the nobles, the group continue on finding themselves in Grove 16 which Hatchan explains is a lawless region of the island. He goes on to explain that Grove 1-29 which make up the interior of the island are like this while the surrounding Groves house the entertainment and shopping districts. Finally after a bit of traveling, they reach Grove 13 and a bar where the coating engineer is said to stay. Upon entering they meet the owner of the bar Shakuyaku (Shakky for short), a former pirate and friend of Hatchan. After the usual meet and greet, Shakky tells them the mechanic (Silvers rayleigh) is not there though has not left the island. Hearing this, the group agree on searching for him to which Shakky warns them to be careful in doing so, as since the Straw Hats arrival, that now make eleven rookie pirate with over 100,000,000 Berri (money in one piece) bounties on them that have reached the Red Line. Luffy being the second highest of the ranks. The eleven rookie pirates, also know as the eleven supernovas on the island, are Capone "Gang" Bege (138,000,000 Berri), Jewelry Bonney (140,000,000 Berri), Basil Hawkins (249,000,000 Berri), Eustass "Captain" Kid (315,000,000 Berri), Scratchmen Apoo (198,000,000 Berri), Urouge (108,000,000 Berri), Killer (162,000,000 Berri), X Drake (222,000,000 Berri), Trafalgar Law (200,000,000 Berri), Roronoa Zoro (120,000,000 Berri), and Monkey D. Luffy (300,000,000 Berri).
Finished at the bar, Luffy's group soon head out to look for Rayleigh. In the midst of looking for Reayleigh, Keimi gets kidnapped. Back on the Sunny, Franky, Usopp and Sanji are taking a break when they get a calls revealing Chopper on the other end, he frantically informs them that that Keimi was kidnapped. And to making matters worse is that they do not know which group took her and where she is since the island is very big and there are many human shops.To which Sanji reveals he's calling the Flying Fish Riders. The Flying Fish Riders then split up to find kidnapping teams while a few go off to collect the remaining Straw Hats.
In a shopping mall in Grove 30, Robin explains to Nami the history of the relationship between human, fish, and mermen. Two hundred years ago, the Fishmen race was classified as just that, fish, and were persecuted by humans. Even with their superior strength, human numbers outweighed their own with kidnapping and slave trade being the most common of methods on the Fishmen. Finally the World Government signed a treaty with Fishman Island and these method were abolished though Sabaody Archipelago still continues this trade. As she finishes the explanation with her theory on why Hachi and Keimi have to hide their true form, some of the Fish Riders arrive with Franky quickly explaining what happened to Keimi.
We then shift to Grove 1 which is home to an human auction ground. The kidnappers having given the auction house keepers Keimi while Roswald and Shalulia soon arrive at the house. Also there are Captain Eustass Kid, Killer and their crew, as well as Trafalgar Law. Meanwhile, in the waiting room of the building, Keimi is put into a cell, dreadfully waiting to be sold into slavery. Keimi then notices an man next to her, When asked who he is, the culprit just claims hes an old man that cannot ignore a young girl. This man however turns out to be none other then Silvers Rayleigh, which we discover was the "right hand" of the last pirate king.
After all of the strawhats arriving at the auction house, excluding Luffy and Zoro, Franky suggests using force to save Keimi, but is reminded that the nobles could be inside and could alert the admirals. Nami suggests they then play by there rules and try to buy Keimi back. Keimi is soon revealed having been fitted with an explosive collar and put into a giant fishbowl. After introduceing her to the crowd prompting Nami to get ready to bid for her. However Charloss (A World Noble) blindsides her and everyone in the house with an instant bid of 500,000,000 Berrie. Needless to say, no one has the money to outbid him.
Keimi's auction was beginning to close, until Luffy and Zoro literally crash into the auction house, The Straw Hats themselves were astounded by the sudden arrival of their two most powerful members, as was everyone else in the auction. Upon seeing Keimi, Luffy rushes the stage despite the protest of Hachi, who is forced to use his remaining arms to try and restrain him. This unfortunately reveals his identity as a Fishman to the crowd, and they immediately raise a panic, confirming Robin's earlier story of discrimination against fish people.
A shot suddenly rings out, stopping the commotion. Charloss has shot Hachi with his pistol, much to the horror of the Straw Hats, Papagg, and Keimi, who pounds furiously on her fishbowl. Charloss then begins to gloat while Luffy makes his way toward the world noble. Hachi tries to stop him, reminding Luffy about the promise not to harm them and citing the fact that he was a pirate and that he deserved it anyway. He apologizes further, stating he only wanted to make up his past actions to Nami and help any way he can but only got in the way. Charloss hears enough and tries to shoot him again. Luffy, already angered, no longer restrains himself and, and not caring about the rules anymore, gets up and punches Charloss in the face. The whole room is speechless after such an attack (save for Law and Kid who cannot help but smirk) while Luffy apologizes to his crew for the attack though they understand given the circumstances and were even indifferent (Zoro even commenting he wanted to slice Charloss), instead commenting that this recent development had just made everything less complicated as they are, after all, Pirates.
This being the ending of book 51 of One Piece, until the next book is more explanatory on the action taken afterwards in the auction house and other things.
