Another way is through a prophecy. In the fanfiction, there could be a prophecy that only Naruto and female Madara together can save the shinobi world from a great disaster. At first, they don't believe it, but as the signs of the disaster start to appear, they are forced to work together. As they spend time together trying to prevent the disaster, they learn about each other's pasts, hopes, and dreams, which leads to a deep emotional connection.
In fanfiction, Tsunami might have a special ability that can soothe the Kyuubi's wild nature. Naruto, being the host of the Kyuubi, is amazed by this. They start to work together, with Tsunami using her ability regularly on the Kyuubi. This leads to a more harmonious relationship between Naruto and the Kyuubi, and also a deep friendship between Tsunami and both Naruto and the Kyuubi as they rely on each other more and more.
The relationship can start with mutual curiosity. Naruto is always open to new things and people, and Female Zetsu is a mysterious being. So, Naruto might be intrigued by her and start to interact with her more, which begins their relationship development.
The relationship can start with mutual respect. For example, if female Naruto shows great courage in a battle, Minato, who values bravery, will start to notice her. Then they can have small interactions like sharing their thoughts on ninja philosophy which will bring them closer.
The relationship can start with mutual suspicion. For example, Naruto initially thinks the female Akatsuki member is just another evil foe. But as they interact more, he realizes she has her own reasons for being in the Akatsuki. This realization can be the first step in developing a more complex relationship.
To develop their relationship in fanfiction, one approach could be to give the female Kurama a backstory that makes her more relatable to Naruto. Say she was once a normal fox in the forest before being transformed into a powerful being. Naruto, with his kind heart, would be sympathetic to her situation. They could also have moments of cultural exchange. Naruto could teach her about human traditions, and she could share with him the ancient knowledge of the fox spirits. This exchange of ideas and experiences would help build a strong relationship between them. Moreover, having them face internal conflicts together, like Naruto's struggle with his own power and the female Kurama's identity crisis, would also strengthen their bond as they support each other through these tough times.
In the fanfiction, the relationship might develop through a series of challenges. For example, Naruto might need to rescue female Orochimaru from a situation where her own past actions have caught up with her. This act of selfless heroism on Naruto's part would make Orochimaru re - evaluate her view of him. She would start to see him as someone different from the other shinobi she has known. As they spend more time together, they would start to understand each other's motives and dreams, leading to a deeper relationship.
Their relationship could start with mutual mistrust. Inuyasha might be skeptical of Female Shippo's motives or abilities at first. But as they face common enemies together, they begin to respect each other. For example, if they team up to fight a demon that is causing chaos in a village, they see how each other fights and starts to rely on one another.
A fanfiction story could start with Naruto being in a desperate situation where he feels that the normal path to peace is not working. So, he decides to team up with Obito and Madara. At first, they seem to be working towards a common goal. But then, Naruto realizes that their means are too extreme. For example, he discovers that the Infinite Tsukuyomi they plan would take away people's free will. He then has to find a way to stop them while still maintaining some sort of alliance. This could lead to a complex web of relationships and power struggles within the group.
There could be a shift from enmity to a begrudging respect. Madara has always been a powerful and feared foe, but with Naruto being stronger, Madara may have to accept Naruto's superiority. Naruto, on the other hand, would likely try to understand Madara's motives better and might try to reform him rather than just defeat him.
The relationship can be developed through shared battles. When they fight side by side against foes, they can start to trust each other more. For instance, if they face a powerful enemy that neither could defeat alone, they would rely on each other's strengths.