Another scenario could be that Naruto is tricked into killing the Kyuubi. Maybe an enemy manipulates him into believing that the Kyuubi is about to break free and cause chaos. Without fully understanding the situation, Naruto takes action. This would lead to a lot of self - reflection and guilt for Naruto as he realizes what he has done.
In some fanfictions, Naruto might kill the Kyuubi to gain ultimate power. He could absorb its chakra in a way that completely destroys the Kyuubi's consciousness. This could be a dark turn for Naruto, as the Kyuubi has been both a curse and a source of strength for him. However, it would also mark a new chapter in his journey, where he has to deal with the consequences of such a drastic act.
In this fanfiction, the female Naruto might have a different approach to taming the male Kyuubi. Instead of the usual power struggle, she could use her kindness and understanding. For example, she might offer to share her emotions with the Kyuubi, making him more empathetic towards humans and leading to a more harmonious relationship between them.
One example could be the Kyuubi making Naruto's hair change colors randomly as a prank. It would be really funny to see Naruto's reaction when he looks in the mirror and sees his blond hair has turned purple or green. Another idea is that the Kyuubi could make Naruto's voice sound like a squeaky mouse whenever he tries to talk seriously. This would cause a lot of confusion among his friends.
One idea could be a story where Naruto discovers the female Kyuubi's unique powers and Anko gets involved in their journey. Maybe they team up to face a new threat in the shinobi world. The female Kyuubi could have a special bond with Naruto that Anko initially doesn't understand but gradually comes to respect.
Another aspect could be the family history. Since Naruto is the grandson of the Fem Kyuubi, there could be a whole backstory about how his parents met. Maybe his mother was a normal human who had a special encounter with the Fem Kyuubi's son (Naruto's father). This could add a lot of depth to the Naruto universe and also explain some of the unique traits Naruto has that are not present in the original story.
A possible fanfiction could be set in an alternate universe where Naruto, Kyuubi, and Tsunami are all part of a prophecy. They have to journey together to find a sacred relic that can either save or destroy the ninja world. Along the way, Naruto has to constantly balance the power of the Kyuubi within him, and Tsunami uses her survival skills and knowledge of the world to help them overcome various obstacles.
One idea could be that Naruto was experimented on by a secret organization in the fanfiction. They erased his emotions to turn him into a weapon against the Hidden Villages. This could lead to a story where his friends try to restore his emotions and bring him back to his true self.
A possible fanfiction plot could involve a female Kyuubi family member who is cursed. Naruto, being the hero he is, tries to break the curse. Along the way, they face many challenges together, and in the process, Naruto and the female Kyuubi develop a deep bond. This bond not only changes their relationship but also has an impact on the entire shinobi world as it shows that humans and the Kyuubi can co - exist in harmony.
One idea could be exploring Naruto's growth not just in terms of power from the Kyuubi, but also his emotional and mental growth. For example, how he overcomes the stigma of being the Kyuubi's host among the villagers who once feared and hated him. This could involve his relationships with characters like Iruka, who was one of the first to see Naruto as more than just a container for the Kyuubi.
One idea could be that Naruto, with the power of the Kyuubi, somehow ends up in the Rosario Vampire world. He could use his ninja skills and the Kyuubi's chakra to face the various supernatural threats in that world. Maybe he teams up with Tsukune and the other characters to protect the school from an even greater evil.
In a fanfiction, Fem Naruto might be training in a new jutsu while wearing the sports bra. The Kyuubi, being a part of her, gives her advice in her mind. The sports bra could also have a special fabric that reacts to the Kyuubi's chakra, creating a unique visual effect during her training.