Arlong Park Arc

The Arlong Park Arc, also called the Arlong Arc, is the fifth story arc of the East Blue Saga. After Nami steals the Going Merry, Roronoa Zoro, Usopp, and later Monkey D. Luffy and Sanji (along with Johnny and Yosaku) set after her and wind up in Cocoyasi Village, Nami's hometown ruled by the tyrannical Fishman Arlong. It is here that Nami's past and true motives come to light. The arc begins with the end of the Baratie Arc, starting off with Luffy, Sanji, and Yosaku heading for Arlong Park in a small boat. To pass the time, Yosaku tells them about the Shichibukai and how this relates to their current destination, Arlong Park. When Sanji doubts that Nami is heading there, Yosaku explains that they were able to estimate her course after he and Johnny had suspected the connection between the two before they were thrown off the Going Merry. The two had noticed that Nami had been interested in their copy of Arlong's wanted poster, and her behavior quickly became suspicious when they told her that Arlong recently had become more active. Meanwhile, Nami arrives at Arlong Park in the Going Merry. Once she arrives at the park's gate, a boy confronts her, trying to fight Arlong for the death of his father.   Nami slaps him and gives him some money to make him go away.

After this, Arlong and his crew are introduced, and it is revealed that Nami is part of Arlong's pirates. Usopp, Zoro, and Johnny arrive at the island, but Usopp and Johnny freak out once they discover the island, and seeing that two Fishmen have spotted them, abandon ship, leaving Zoro (who was tied up by the two to, ironically, prevent him from fighting the Fishmen) to be captured by the Fishmen. Usopp and Johnny find themselves in the remains of Gosa Village, with all the houses upturned. One of the Fishmen from earlier spots the two and starts chasing them. Johnny manages to escape and hide, while Usopp ends up getting attacked by the same boy from earlier because he thought that Usopp was a Fishman; however, a woman manages to stop him. Seeing the real Fishman getting closer, Usopp readies to fight him, but gets knocked out by the woman, who claims it not a good idea to fight one of the Fishmen. Meanwhile, Luffy, Sanji, and Yosaku continue sailing, and just as they take a break to eat, they encounter a giant sea cow that is attracted to their food. Luffy punches it at first, prompting Sanji to reprimand him for it. But when he realizes the sea cow sees them as food, he quickly subdues it with one kick. The three then strap the boat to the sea cow and use it to tow them to the island. Meanwhile, Usopp awakens in the house of the woman, who introduces herself as Nojiko. After convincing the boy to give up on his quest for vengeance, Nojiko reveals to Usopp that she is Nami's sister and the island is her hometown, as well as Nami being part of Arlong's crew. Usopp then panics after he realizes what he has gotten Zoro into. Meanwhile, Zoro is brought to Arlong Park, where he finds out about Nami's allegiance to Arlong. After some banter, in which Arlong proudly states that Nami is the type of person who would betray even her own family for the sake of riches (which visibly disturbs Nami), Zoro throws himself into the water to test Nami's allegiance. She saves Zoro but beats him to reassure the Fishmen that she is still part of Arlong's crew.