Nami's origins lie as a war orphan from the destroyed Oykot Kingdom. Discovered as an infant alongside adoptive sister Nojiko, Marine Bell-mère brought them to Cocoyasi Village and raised them. Despite poverty, she honed exceptional cartography skills, dreaming of mapping the world. This dream shattered when the fish-man pirate Arlong conquered Cocoyasi, murdered Bell-mère, and forcibly recruited Nami for her navigation talents. Arlong promised the village freedom for 100 million berries, leading Nami to spend eight years stealing from pirates while secretly mapping for Arlong. Her betrayal of the Straw Hat Pirates during the Baratie Arc stemmed from this obligation, though she later genuinely joined after Luffy defeated Arlong and liberated her village. She replaced the Arlong Pirates' shoulder tattoo with a mikan and pinwheel design honoring Bell-mère and Genzo. In the Skypiea Arc, Nami's navigation expertise proved critical for reaching the sky island via the Knock Up Stream. Her meteorological knowledge identified unique Skypiean weather patterns. On Angel Island, she bonded with local Conis and borrowed her "Waver" cloud-skimming vehicle, inadvertently discovering forbidden Upper Yard territory. This trespass resulted in the Straw Hats being declared criminals. Separation from the crew led to her capture alongside Chopper and Robin by a giant shrimp. Though rescued, she later witnessed Conis's coerced betrayal under Enel's orders. Nami participated in Enel's "Survival Game" within Upper Yard, facing deadly trials. She demonstrated resourcefulness with her Clima-Tact weather-manipulation staff, overcoming Enel's priests like Satori's siblings Hotori and Kotori alongside Gan Fall. Her observational skills navigated treacherous terrain and decoded weather-based challenges. After reuniting with crewmates inside a giant python, she contributed to uncovering Skypiea's history involving the lost Shandoran civilization and its golden bell. The arc concluded with her witnessing Luffy's victory over Enel and the fulfillment of the "Noland the Liar" legend. Following the timeskip, Nami's meteorological abilities expanded after training on Weatheria, mastering advanced climate prediction and manipulation. Her weapon evolved into the Sorcery Clima-Tact, incorporating dial technology and later merging with the sentient thundercloud Zeus from Big Mom, significantly enhancing her combat capabilities. During the Whole Cake Island and Wano Country Arcs, she applied navigation skills through lethal climates like the New World's unpredictable waters. In Wano, she temporarily assumed the alias "O-Nami" for undercover operations. Her tactical intelligence guided crew decisions, such as rerouting part of the crew to Zou during the Dressrosa conflict. Nami appears across multiple films and specials. The TV special "One Piece Fan Letter" depicts a young admirer seeking to deliver a letter to her during the Sabaody Archipelago reunion. Films involving Oda's direct input, like "Strong World," showcase her advanced weather prediction abilities surpassing scientific equipment. While movies 8 and 9 adapt earlier Arabasta and Drum Island arcs, no film specifically re-tells the Skypiea narrative. Her character consistently emphasizes financial management of the crew, navigation through deadly seas, and combat using weather-based tactics.