In many fanfictions, the Kyuubi's possessiveness is a result of their unique bond. Since they share a body, the Kyuubi might see Naruto as an extension of itself. So, it could be shown as the Kyuubi being extremely territorial about Naruto. It might not tolerate any external entity trying to control or manipulate Naruto, and will assert its power to keep Naruto under its 'protection' in a very possessive manner.
In this type of fanfiction, the fem Kyuubi's possessiveness might be manifested in her protecting Naruto at all costs. She could be overly vigilant and not allow any harm to come near him. This could lead to her interfering in battles or situations where Naruto might be in danger, even if he doesn't necessarily need her help all the time. She may also try to monopolize his time, not wanting him to go on missions with other people or make new friends. Her possessiveness could also be expressed in a more emotional way, like getting sulky or angry when Naruto doesn't pay enough attention to her.
Anko's possessiveness in Naruto fanfiction may be shown in the way she gets jealous easily. If Naruto gives more attention to another character, Anko might sulk or become angry. She could also be possessive in terms of protecting Naruto from perceived threats. Even if the threat is minor, she'll be very vocal and physical in her defense of Naruto, which shows her possessive nature.
In many fanfictions, Sasuke's possessiveness is tied to his deep emotional connection with Naruto. He might feel that Naruto is the only one who truly understands him. So, when Naruto spends time with others, Sasuke can get jealous or possessive. For instance, there are stories where Sasuke gets moody when Naruto is training with other ninja. He doesn't like sharing Naruto's attention. This shows his possessive side in a more complex emotional way.
Well, in fanfictions about Naruto, Kushina and Kyuubi, their relationships can vary greatly. Some fanfictions might focus on how Naruto inherits not only the Kyuubi's power but also some of Kushina's traits. For example, Kushina was known for her strong will, and Naruto might be shown to have an even stronger will because of her influence and the presence of the Kyuubi. The Kyuubi could be portrayed as a protector of Naruto in a sense, especially when it comes to threats that are related to Naruto's family history. And Kushina could be like a spiritual guide for Naruto when it comes to dealing with the Kyuubi's power.
Through his actions. For example, he could mark Naruto in some way, like leaving a small, invisible mark that only he can sense on Naruto. This would be a sign of his possessiveness.
She might be overly protective of Naruto in fanfiction. For example, she could prevent other characters from getting too close to him or interfere when she thinks Naruto is in a potentially harmful situation.
Naruto might be initially confused. He is used to being friendly with everyone, and this sudden possessiveness from Fem Gaara could catch him off - guard. So he may just try to talk to her to understand why she is acting this way.
In the fanfiction, Kushina's possessiveness could be manifested in various ways. She might be very controlling of Naruto's daily activities. For instance, she would decide what he eats, when he sleeps, and how he spends his free time. Also, if there are any female characters showing interest in Naruto, Kushina would be quick to step in and make it clear that Naruto is 'hers' in a sense. This could create some interesting conflicts in the story, as Naruto might feel suffocated by her over - protectiveness at times, while also understanding that it comes from her love for him.
Well, Kyuubi might be possessive of Naruto because they have a unique bond. Kyuubi has been inside Naruto for a long time. They've shared experiences, and Kyuubi may see Naruto as its own in a way. Also, Naruto has sort of tamed Kyuubi to an extent, and this might make Kyuubi feel like Naruto is special to it, so it shows possessiveness.
One possible reason could be that in the Naruto universe, Naruto has a special connection with the Kyuubi. As a female Kyuubi in fanfiction, she might feel a stronger emotional bond towards Naruto. She may see Naruto as her sole companion or the one who truly understands her, which leads to her possessiveness.