Another plot idea could be that Naruto's transformation into a female makes her more in tune with the chakra of nature in a unique way. This could be related to some ancient ninja lore about female ninjas having a special connection to nature, and she uses this new ability to overcome powerful enemies and protect the village.
Maybe in this fanfiction, Naruto as a female could develop a different kind of relationship with Sasuke. Since the dynamic between male - female friends can be distinct from male - male friendships, it could lead to new story arcs and character growth for both of them.
One idea could be that as females, they have a different dynamic in their friendship. Maybe they bond over more traditionally feminine interests while still having their ninja goals. For example, they could share a love for flower - arranging which is a contrast to their usual battle - focused activities.
One plot idea could be that Naruto is turned into a monster during a powerful and dark jutsu gone wrong in a battle. He then has to struggle with his new form while his friends initially fear him but later try to find a way to turn him back. Another could be that an ancient curse is placed on him, turning him into a monster, and as a result, he has to go on a journey to find the source of the curse to break it.
A great plot could involve the female Naruto being sent on a diplomatic mission to another village. There, she discovers a conspiracy against the Hidden Leaf Village and has to use her wits and ninja skills to expose it and prevent a war. Along the way, she also forms unexpected friendships with some of the villagers from the other village, which helps her in her mission.
Maybe in this fanfiction, Naruto has to hide his true nature from his friends at first. As he was once the Kyuubi, he might be afraid of being rejected. This could lead to some really tense and emotional moments when his friends start to suspect something is different about him.
One possible interesting plot point could be how Naruto, as a female, copes with the new social dynamics in the ninja world. For example, she might face different expectations from her male counterparts. Another could be how her relationship with Kurama changes. Since Kurama is a powerful and somewhat unpredictable force, a female Naruto might interact with it in a more empathetic or different way compared to male Naruto.
One idea could be that Superboy is hit by a strange alien device that changes his gender. He then has to deal with the new physical limitations and social expectations while still trying to be a hero. For example, he might struggle with the different way people treat him as a girl and how to use his powers in a more feminine body.
One idea could be a modern-day high school student who gets turned into a vampire and has to hide it from their friends and family while dealing with the newfound powers and bloodlust. Another could be a historical setting where a vampire turns a noble during a time of war and they must navigate the political and social implications. Or perhaps a story about a vampire who turns a detective, and together they solve supernatural crimes.
In 'FNAF Turned Human Fanfiction', a great plot idea could be the human - turned - animatronics trying to find a way back to their original forms. They could face challenges like discrimination from humans who remember them as terrifying animatronics. Also, their new physical forms might have some special abilities or weaknesses that add to the story.
One idea could be a scientist who is experimenting on artificial intelligence and accidentally gets his own consciousness transferred into a robotic body. He then has to deal with the new limitations and capabilities of the robotic form while trying to find a way to reverse the process.
One plot idea could be that Link, as a girl, has to hide her true identity in a world that doesn't expect a female hero. She could face challenges like being underestimated at first but then prove herself in battles. Another could be that she forms unique relationships with the other characters, like a different kind of friendship with Zelda. Maybe she also has to deal with newfound emotions and how they affect her heroic duties.