In this fanfic, a possible plot could be that Naruto, now a woman, decides to use her new form to her advantage in undercover missions. She could infiltrate enemy groups more easily as a woman. Also, her bond with her sensei Kakashi could change. Kakashi might have to adjust his training methods for her, and Naruto could learn different aspects of ninjutsu and strategy that were more suited to her new gender.
One idea could be that Naruto discovers he has a special power that only activates at night. For example, he might be able to communicate with nocturnal animals and they help him in his ninja missions. Another could be that at night, Naruto's appearance changes in a way that gives him an edge in stealth, like his hair turns black to blend in with the darkness better.
One idea could be exploring the backstory of one of the minor characters in more detail. For example, the character who is the best archer in the group. You could write about how she came to be such a skilled archer, her training, and any personal challenges she overcame.
An interesting plot idea for Naruto fanfic might be to focus on the life of a minor character. For instance, what if we told the story of a genin who never made it to be a chunin but still had a significant impact on the village in some other way? Or a story where all the ninja abilities are suddenly switched among the characters, and they have to adapt to these new powers while still facing their usual enemies. This could lead to some really fun and unexpected character interactions.
One idea could be that Harry's transformation into a monster girl makes him/her (depending on how the transformation affects gender identity) discover a whole new world of magical creatures that were previously hidden from normal wizards. He/She could form unique bonds with these creatures and use their newfound abilities to solve mysteries in the wizarding world.
A possible plot could be that the snake woman is from a lost clan that has a connection to the Nine - Tailed Fox inside Naruto. She comes to Naruto seeking his help to revive her clan. Naruto hesitantly agrees and they embark on a journey full of mystery and adventure.
One idea could be that Naruto is transported to the DC universe and teams up with Wonder Woman. They could combine their unique combat skills, like Naruto's shadow clones and Wonder Woman's lasso and super strength, to fight a common enemy. Maybe a powerful villain from Naruto's world has also found a way into the DC world.
One idea could be that Naruto discovers a hidden power within Shenron. For example, instead of just granting wishes in the traditional way, Shenron could offer Naruto a special training regime that enhances his already powerful jutsu. This could lead to Naruto facing new and even stronger enemies.
Another plot could be Samui getting involved in a time - travel adventure. Maybe she gets sent back in time to the era when the ninja world was just being formed. She then has to use her modern - day knowledge and skills to survive in that primitive yet dangerous time, and also has the chance to change the course of ninja history in small ways.
One idea could be that Tayuya, after being defeated, has a change of heart and teams up with Naruto to fight a new common enemy. They could learn from each other's skills and jutsu.
One idea could be Shinachiku going on a journey to discover his own unique ninja skills, different from his father Naruto. He could encounter new enemies and make unexpected allies along the way.