Nami's first appearance in One Piece was an eventful one for the series as it introduces one of the most integral characters to the Straw Hat Pirates and the whole story itself. She first appears in Chapter 8 of the manga, while in the anime, she holds the distinction of being the very first major character introduced, appearing even before the main protagonist, Luffy.
It can be said that Nami's character has been in development even in Eiichiro Oda's earlier works. During his "Romance Dawn" concept stories, there were prototypes of Nami: first in Version 1, she was a Silk character; then in the next versions, she was named Ann. This would set down the roots of what eventually evolved into the character of Nami, showing just how the author refines and develops his characters.
Nami's proper introduction within the One Piece storyline is in the Orange Town Arc. This marks the point at which Luffy first lays eyes on her, setting the scene for their later relationship as comrades aboard his ship. Although if one is sharp-eyed, she might be glimpsed far back in Zoro's introductory scenes. In this very early cameo, one also sees some of Oda's planning and foreshadowing, two of the things that have become characteristic of a One Piece narrative.
First off, Nami is introduced in the series as a slim young woman with brown eyes and orange hair. Since the very first scenes, she has been developed as a talented thief and navigator but also as a quite complex character whose past has its mysteries. This can be traced back to the very beginning since Nami's actions and intentions remain at first very unclear, thus giving mystery to her character.
This, in effect, makes Nami the very first principal character to meet with the audience, adding more emphasis on her importance. This could be interpreted as emphasizing her importance to the story and drawing the viewer directly into the world of One Piece through her. This also sets up the relationship dynamic between Nami and Luffy that becomes a central relationship in the series.
Nami's introduction is crucial not only to her character but also to the whole framework of the Straw Hats. She was the second member to be added to Luffy's group after Zoro, even though she was formally inducted way later into the series due to her complicated situation. This delayed official joining adds depth to her character arc and anticipation for the moment she becomes a full-time member.
In the Netflix live-action adaptation, Nami's first appearance goes very much to the point. She makes her first appearance in Season 1, Episode 1, titled "Romance Dawn," just like in the original series. The live-action adaptation fleshes out a complicated development for Nami, and from the very beginning, it spells out her torn loyalties and hidden motives.
This first appearance also firmed up important facets of her character that would be revisited throughout the series: her navigation skills, her cunning, and how she can manipulate situations for personal gain. These traits, though at times first offered in a rather morally gray sense, would prove to be useful tools for the Straw Hats.
Nami's visual design when she first appears is rather noteworthy. While her outfit has changed a number of times over the course of the series, this first design establishes the basic elements of how she is going to look: orange hair, slim build, confident air. These are just a few visual keys that not only help make her instantly recognizable but set her apart from a number of other characters across the vastness of One Piece.
Her first appearance also sets up several themes relevant to her character arc. Nami is introduced as a thief whose motives are ambiguous, setting up the payoff regarding her past with Arlong and her village later in the series. This double introduction is such that it gives meaning to Oda's ability in creating characters that are deep and full of unknown complexities.
From a narrative standpoint, Nami's introduction helped to establish the tone and themes of One Piece. She brought an aspect of realism into a world full of fantastic powers and larger-than-life characters. This feature makes her, to a certain extent, relatable and really spotlights how skill, brains, and determination can be decisive factors in the One Piece world, since she has no superhuman abilities or Devil Fruit powers at the beginning of the series.