At first, the relationship might be strained. Naruto could be jealous of his sister's favored status. However, as the story progresses, his sister might start to see the injustice Naruto faces and try to bridge the gap. They could gradually develop a more understanding and loving relationship.
Another storyline could involve Naruto's sister being trained more rigorously by the village elders because they see more potential in her. Naruto, feeling neglected, then goes on a self - discovery journey to find his own strength outside the village's traditional training methods. As he grows stronger, his sister realizes the mistake of the elders and tries to make it up to Naruto.
They could start by having some friendly competitions. For example, in a race to the top of a mountain or a sparring match. This would not only show their bond but also their competitive nature as siblings.
A possible plot is that the neglected twin sister is actually a key to an ancient prophecy that the village doesn't know about. As she grows up, she starts to have strange dreams related to the prophecy. She then embarks on a journey to figure out what it all means. Along the way, she befriends some unlikely allies, like a group of rogue ninjas who have their own reasons for helping her. In the end, she reveals the truth about the prophecy and her importance to the village, which makes Naruto and the others regret their neglect.
He might try to prove himself. Naruto has always been a determined character. He could focus on his ninja training more intently, aiming to show everyone his worth despite being neglected. Maybe he'd also start to distance himself a bit from his family situation and form closer bonds with his friends like Sasuke and Sakura, who might understand and support him through this tough time.
It's popular because it explores a different side of Naruto's story. The idea of him having a sister who cares when others don't adds an interesting dynamic. People like the concept of family loyalty and the sister being a support system that Naruto was lacking in the original story.
In such a fanfiction, perhaps the village's needs are always put first by Naruto, and his sister gets the short end of the stick. For example, he might not be there to protect her when she faces some bullies in the village just because he's too busy with village affairs. This could cause her to doubt Naruto's love for her, and she might even consider leaving the village in search of a place where she feels more valued.
It could be a member of Naruto's family who is fueling the neglect. Maybe an older relative who believes that the sister has more potential or is more worthy of attention and resources. This person could actively try to keep Naruto down.
Another aspect could be the relationship between Naruto and his sister. If she is the favored one, she might initially be oblivious to Naruto's pain. But as the story progresses, she could realize how wrong it is and try to make it up to him. This could lead to a complex family dynamic exploration in the fanfiction.
Her character might develop through self - discovery. Since she's neglected, she has to rely on herself. So she starts exploring her own strengths and weaknesses. For example, she might find out that she's really good at stealth because she's always had to hide her feelings. As she faces various challenges, like dealing with bullies in the village or trying to prove herself to her family, she becomes more confident and assertive.