Shonen manga has a messy track record when it comes to writing strong, three-dimensional female characters. And while One Piece is certainly not the first to do well by its female characters, it has also stayed consistent with them -- especially its orange-haired leading lady, Nami.
Early on in One Piece, Nami repeatedly catches readers and viewers off guard. She's the first non-marine character Luffy meets who openly hate pirates, a stark contrast from our cheerful future Pirate King. In fact, she outright pawns the rubber boy off to Buggy the Clown to gain the Pirate Captain's trust and steal a map to the Grand Line. It's only when she sees Luffy protecting the dog Chouchou and his treasured pet store that she reconsiders her prejudices against all pirates. Nami soon joins Luffy's cause, but not officially until the Arlong Park arc -- where her troubled past is revealed.
Nami was adopted by a former marine officer named Belle-mere, alongside her adopted older sister Nojiko. The family scraped by but lived peacefully in Cocoyashi Village. Even from an early age, Nami possessed a great talent for navigation, which Belle-mere encouraged. This is how we learn of Nami's dream: to one day chart a map of the entire world. They didn't have much besides Belle-mere's tangerine groves, but the young woman instilled confidence in her daughters that there will always be better days over the horizon. Tragedy struck, however, when the menacing Arlong Pirates took over the village and imposed a burdensome tax on all the citizens.
Belle-mere only had enough money to either save her own life or her two daughters so the strong-willed mother gave her life to protect the young girls. But Arlong's cruelty didn't end at killing Nami's mother -- after seeing her skills at cartography, he forced Nami to start drawing maps for his crew. Arlong did strike a deal with the young girl, promising that if she could one day amass 100 million Beli, then he would allow her to buy Cocoyashi Village back from him.
It's clear why Nami has such a fixation when it comes to money. If she only had more of it, her mother wouldn't have died as a result of Arlong's wickedness. Nami gets close to reaching that 100 million, but Arlong goes back on the deal he made, and in a blind moment of frustration she begins stabbing the tattoo he branded her with. Luffy is the one to stop her, and in a moment of desperation, Nami finally learns to rely on the people who care about her and asks her friends for help.
After Arlong's defeat, Nami officially joined Luffy's crew as their navigator, essentially the most vital role for sailing on a ship. She's the one who charts a course to each island and ensures they don't run into a storm or disaster along the way. Like every Straw Hat Pirate, Nami has her part to play, and it's her presence that makes them such a formidable and effective pirate crew.
Furthermore, One Piece creator Eiichiro Oda's complete disinterest in forming romance between the Straw Hats leaves Nami with much more agency and reliance instead of being a simple love interest. She has her own reasons for being on this crew and the role she fulfills isn't in service of romantic tension, but because her friends care about and rely on her.
Yet when a battle arrives it's usually Luffy, Zoro, and Sanji who fight first, and despite her effectiveness as a navigator, this makes Nami feel like a burden. During the Alabasta arc, she asks Usopp to design her a weapon that only she can utilize. Although her Clima-Tact starts out as a tool for silly party tricks, it eventually starts to work for her -- to the point that she can call upon thunder and lightning to overtake her enemies.
When Sanji's chivalry gets in the way of him fighting Kalifa at Enies Lobby, Nami steps up to duel the female assassin in his place. This is where we see Nami use her intellect -- since she can't brute force her way to victory, she has to understand her opponents' abilities and exploit their weaknesses. Kalifa's Bubble-Bubble devil fruit powers can reduce Nami's strength and restrict her movement, but when she sees the water from the exposed plumbing pipes evaporating the bubbles, she formulates a counter against the assassin using rain and mirages.
Nami may not be the first to rush into a fight in One Piece, but she always steps up when the moment calls for it. Her loyalty to her crew cannot be overstated and despite what her greedy personality may suggest, she can't help but show compassion to children. When she, Sanji, Chopper, and Franky are escaping from Caesar Clown's laboratory, they run into the experimental children. The kids beg the pirates to save them and despite not owing them anything, Nami can't ignore them, stating, "These are children crying to us for help! How can we possibly turn our backs on them?"
Likewise, Nami's loyalty continues to progress as One Piece goes on. During the Skypiea arc, the lightning-fast antagonist Eneru orchestrates a Battle Royale between his army, the Shandians and the Straw Hats, and Nami ends up being the last one remaining. The navigator half-heartedly agrees to join Eneru on his journey "to the World of Dreams" rather than risk the chance of death like Zoro or Wyper.
Jumping ahead to Chapter 995 during the Wano arc, Nami is trapped by one of Kaido's Tobiroppo, Ulti, but the Pachycephalosaurus devil fruit human says she'll spare Nami's life if she admits that Luffy will never become King of the Pirates. Yet even with her life in danger, Nami can't bring herself to mock her captain's dream, saying instead, "Luffy will never stop until he's King of the Pirates."
Nami has grown leaps and bounds from the pirate-hating cat burglar of the small East Blue Village. Luffy couldn't have made it this far without her by his side to chart a course to every new island (or deathtrap) the rubber-brained captain will immediately cause trouble in. Nami is cautious and greedy, but also intelligent, kind and clever, and will always stand up when the moment calls for it. She's the navigator of the Straw Hat Pirates and the woman who will one day chart a map of the entire One Piece world.