Another aspect could be the family relationships. When Naruto is in Himawari's body, he gets to experience how his family members interact with Himawari on a more personal level. He might realize things he hadn't noticed before about how his daughter is treated and how she feels. And on the other side, Himawari in Naruto's body might gain a newfound respect for her father's responsibilities and the pressure he's under all the time.
Naruto's exuberant and adventurous personality in Himawari's body would surely lead to some chaos. He might be more eager to participate in activities that Himawari would normally be shy about, like showing off in front of classmates or taking on challenges that kids usually avoid.
How about a twist where Hinata was secretly trained by an unknown master all along? And this training was to prepare her for a great prophecy that involves Boruto and Himawari. When the time comes, she reveals her new and unexpected skills to save her family.
One possibility could be that Naruto discovers a new side of Himawari. Maybe she shows an unexpected talent for ninjutsu that Naruto is really impressed by. This could lead to Naruto becoming her biggest supporter and fan, constantly cheering her on during her training sessions.
One possible plot could be that in a sparring session, Himawari, who has been training secretly, surprises Naruto with her newfound strength and accidentally knocks him out. This could lead to a series of events where the village is in a bit of chaos as they wonder how a young girl managed to take down the Hokage. Then, Himawari feels guilty and tries to make it up by training even harder to protect the village in the future.
Well, it could be a story centered around a festival in Konoha. Naruto and Hinata are preparing for the festival, and Boruto and Himawari are super excited. But then some strange things start to happen. Mysterious ninjas appear and seem to be up to no good. Boruto and Himawari get caught up in the mystery, and with the help of Naruto and Hinata, they figure out that these ninjas are actually from a far - off land and were just lost. In the process, the family bond gets even stronger.
Perhaps a major plot twist could be that the body swap is not accidental but part of a bigger plan by a mysterious villain. This villain could be using their body swap to gain access to something that only Ash or Iris can reach in their normal bodies. For example, there could be a special Pokémon or a powerful item. And as they try to figure out how to swap back, they also have to deal with this new threat, which adds a whole new layer of complexity to the fanfiction.
In a Naruto is Vergil fanfiction, it could be that Naruto's connection to Vergil is through a dream - like realm. Every time Naruto sleeps, he enters a world where he meets Vergil and learns from him. Over time, Naruto starts to incorporate Vergil's values into his own. He becomes more focused on power for the sake of protecting those he loves in a more 'Vergil - esque' way, which means he might be willing to make some sacrifices that he wouldn't have considered before, like sacrificing some of his own personal relationships for the greater good of the village.
In a 'Naruto meets Himawari' fanfiction, Naruto could teach Himawari some new ninja techniques. He might share his own experiences from his adventures, inspiring Himawari to be a great ninja.
Well, one possibility could be that Himawari, being from a later generation, somehow travels back in time and meets Kushina. Kushina might see a bit of herself in Himawari's spunk and determination. They could bond over their love for their families. Himawari could learn a lot from Kushina about the Uzumaki heritage and the early days of the Hidden Leaf. And Kushina could be proud to see what her family has become in the future through Himawari.
One possible plot twist could be the comical misunderstandings. For example, Star - Lord in Gamora's body might try to use his usual charm on the other Guardians, but it comes across all wrong because it's Gamora's body. Another could be the way they deal with their enemies. Gamora in Star - Lord's body might have to use his blasters instead of her usual sword, leading to some clumsy but interesting fight scenes. Also, they could learn more about each other's inner thoughts and feelings during this swap. Maybe Star - Lord realizes how much pressure Gamora is under all the time, and Gamora understands Star - Lord's more carefree nature better.