Arlong Park Arc

After Nami flees with the Going Merry, Zoro, Usopp, and Johnny trace her to Cocoyasi Village, her childhood home, only to find it ruled by Arlong and his crew of fish-men, with Nami counted among their number. When Luffy and his new cook Sanji arrive, the truth behind her cold behavior and her membership in the crew gradually surfaces. The arc turns into a fight to break Arlong's grip on both Nami and the village she has been desperately trying to buy back.

Sailing toward Arlong Park, Yosaku fills Luffy and Sanji in on the Seven Warlords and on how he and Johnny deduced Nami's destination from her interest in Arlong's wanted poster. Nami herself reaches the park and is revealed as one of Arlong's pirates. Zoro, separated from the others, is captured and learns of her allegiance firsthand, testing it by throwing himself into the sea, where she saves but then strikes him to keep up appearances. Usopp, meanwhile, is taken in by a woman named Nojiko, who turns out to be Nami's foster sister.

The village's suffering becomes clear: Arlong extorts a monthly fee from every resident under threat of death. When Usopp is captured, Nami appears to murder him to prove her loyalty, though she has secretly spared him. As tensions mount, Nojiko recounts Nami's past to Sanji and Usopp. Years earlier, Arlong demanded a per-head ransom the family could not afford, and their adoptive mother Bell-mère gave up her own life so her two daughters could live, killed before their eyes. Arlong then took Nami for her cartography talent, and she struck a deal to buy back Cocoyasi for one hundred million berries.

The arrangement collapses when the corrupt Marine Captain Nezumi seizes the money Nami has painstakingly saved, and Arlong refuses her demands for an explanation. Driven to despair, Nami stabs at the Arlong tattoo on her own arm until Luffy stops her. She finally asks for his help, and he sets his straw hat on her head before leading the crew to Arlong Park. There the Straw Hats each take down one of Arlong's officers: Zoro overcomes Hatchan despite his wounds, Sanji defeats Kuroobi, and Usopp outlasts Chew. Luffy, his feet trapped in stone and thrown into the sea, is rescued by Nojiko and Genzo, then frees himself to battle Arlong alone. He wrecks the map room where Nami toiled for years and smashes Arlong through his own tower, destroying the park.

Emerging from the wreckage, Luffy declares Nami his friend, and the village celebrates its freedom. Nezumi's attempt to claim Arlong's wealth earns him a beating, though he flees vowing revenge and reports Luffy's victory. Nami replaces her hated tattoo with a tangerine and pinwheel design, and as the crew departs she sprints aboard after pickpocketing the entire village goodbye. The pinwheel Genzo once wore for her is left resting on Bell-mère's grave.

Nami formally joins the Straw Hats as their navigator, finally explaining her earlier hatred of pirates. The arc introduces the fish-men as the series' first non-human race, seeding the racial themes later explored at Sabaody, Amazon Lily, and Fish-Man Island, and it drops Jinbe's name centuries of chapters before his debut. Hatchan would return in his own mini-arc, and the resemblance between Arlong Park and Sabaody Park is later confirmed. Nezumi's report, combined with Luffy's earlier wins, earns Luffy his first bounty of thirty million berries. Momoo the sea cow resurfaces far later under the Caribou Pirates, and the arc plants early seeds for recruiting a doctor and a musician, eventually realized in Chopper and Brook. A feature-length remake, Episode of Nami, aired in 2012.