Well, one possibility could be that Naruto and Himawari are somehow transported to the DC universe. Naruto's powerful ninja skills would be quite interesting in the context of the Justice League. He could use his shadow clones to confuse villains or his rasengan as a powerful attack. Himawari, with her latent Byakugan abilities, might be able to detect hidden threats or weaknesses in enemies. Maybe they team up with Superman and Batman. Naruto could learn about the concept of 'superheroes' in this new world and they could all work together to stop a major threat like Darkseid.
One idea could be a story where Boruto and Himawari discover an old lemon tree in the Hidden Leaf Village. Naruto and Hinata then tell them about a legend that the tree was planted by the first Hokage. The kids decide to take care of the tree and throughout the process, they learn more about their family's history and the importance of nature in their village.
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.
In fanfiction, Naruto and Himawari would bring a whole new cultural aspect to the Justice League. Naruto's ninja code and Himawari's upbringing in the Hidden Leaf Village would contrast with the Western - style heroism of the League. Naruto might be seen as a bit of a wild card by some members at first, but his heart of gold would win them over. Himawari could befriend characters like Cyborg, fascinated by his technology. They would both contribute to the League's diversity, and their unique powers and personalities would change the way the League operates and interacts, making for a more interesting and complex dynamic.
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.
Let's say a traveling merchant brings a rare lemon that has special properties. Boruto is curious and wants to study it. Himawari tags along. Naruto and Hinata are initially worried but then support their children's inquisitiveness. The lemon could be the key to unlocking a new power or it could lead them to a new adventure outside the village, with the family having to rely on each other in unfamiliar situations.
One great idea for a Boruto and Himawari fanfic is a story where they go on a journey outside the village. They might encounter new types of ninjas or strange creatures. Himawari could be the one to sense danger with her Byakugan first, and Boruto would be ready to fight. It would show their growth as ninjas and also their bond as siblings.
The moment when Naruto first realizes his feelings for Hinata during a kiss is often a great moment. It's like a light bulb going off in his head, and suddenly he sees Hinata in a whole new light.
Perhaps in the fanfic, Boruto and Himawari are involved in a festival in the village. They enter a contest together, like a ninja skills show - off. Boruto is a bit overconfident at first, but Himawari keeps him grounded. In the end, they learn more about each other and their combined strength as siblings.