One possible plot could be that Boruto and Himawari travel back in time to the era of the First Hokage. They might witness the founding of Konoha and learn about the original values of the village. Boruto could use his modern - day knowledge of ninja techniques to help in some unforeseen situations, while Himawari's innocent charm could win over the hearts of the past shinobi.
Their powers could actually be beneficial in some ways. Boruto's ability to think on his feet and use his various skills could help in solving some past problems. Himawari's Byakugan could be used for reconnaissance in dangerous situations in the past. But they must always remember that any use of their powers could have a butterfly effect. So they would need to be cautious and consult with each other before taking any major actions with their powers.
Boruto could be developed by showing his growth in responsibility. For example, in the fanfic, he could take on the task of teaching Himawari a new jutsu. This would not only show his skills but also his patience. Himawari, on the other hand, could be developed by showing her becoming more independent. Maybe she decides to go on a small mission on her own to prove herself to Boruto.
The relationship can be shown as a strong sibling bond. For example, Boruto could be protective of Himawari when she is in danger during a mission. Or Himawari could be the one to cheer Boruto up when he is feeling down about his ninja training.
One idea could be a story where Boruto and Himawari discover an old diary of Naruto's from his early days as a ninja. Hinata helps them understand the context and the values their father held. They then use those lessons to face a new threat in the village.
Boruto has the ability to use the Rasengan, which is a very powerful jutsu. He also has the Jougan, an eye power that gives him unique abilities like seeing chakra and some kind of predictive vision.
Boruto and Himawari often have adventures in the village. They might go on small quests together, like looking for a lost pet in the village or helping an old neighbor with their garden. It's all about their daily life experiences filled with friendship and family values.
One great 'Boruto and Himawari fanfic' is 'Sibling Adventures'. It shows their daily life in Konoha, with Boruto teaching Himawari some new ninja techniques in a really cute way. They also have some small adventures together around the village, like finding a lost pet. Another one is 'Himawari's Growth' which focuses on Himawari's development as a ninja under Boruto's guidance. It's really inspiring to see their bond strengthen as she learns.
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.
If they travel together through time, their relationship becomes more of a partnership. They have to rely on each other in a different time period. This shared experience of exploring different eras and facing challenges together can make their bond even stronger. They might discover new things about each other that they never knew before, like Naruto finding out how brave and resourceful Himawari can be in a completely unfamiliar situation.