Adventure could also be a theme. They could be on a journey together, facing various challenges and obstacles, and relying on each other to get through. This can create exciting and engaging stories as they explore new places and situations.
I'm not sure exactly which kirihito x nanami fanfic to recommend as there are many out there. You could try searching on fanfic websites like Archive of Our Own. They have a large collection of fan - created stories and you might be able to find some great kirihito x nanami ones by using their search function.
One idea could be a story where they go on an adventure together to save their world from a dark magic. They face many challenges and in the process, their relationship deepens.
Friendship - turned - more - than - friends is also quite common. They start as colleagues or friends in the 'Jujutsu Kaisen' universe, and in fanfics, it often evolves into a deeper relationship, whether it's romantic or a very close platonic bond with strong feelings. Another theme could be their shared experiences in battles. How they rely on each other in dangerous situations and how that affects their relationship off the battlefield.
Love and loyalty are very common themes. Tomoe's loyalty to Nanami and their budding love story are frequently explored. Also, the theme of sacrifice comes up. For example, one of them might be willing to sacrifice something for the other's well - being. Additionally, the clash between their different natures, human and yokai, can also be a recurring theme in these fanfics.
Love and affection are very common. Since it's a 'x reader' fanfic, the development of a romantic relationship between the reader and Nanami is often central. Another theme is support, like Nanami being there for the reader in difficult situations.
Friendship is a common theme. Nanami Haruka often forms deep friendships with different characters in these fics. Another theme is self - discovery. As he interacts with everyone, he learns more about himself.
You can start by writing down some character sketches of both Kamisama Kirihito and Nanami. Consider their personalities, their strengths and weaknesses. This will help you write their actions and dialogues more accurately. For example, if Nanami is known for her kindness, show that in how she interacts with others in your story. Then, start with a scene that grabs the reader's attention, like a mysterious event that involves both of them.
One common theme is friendship. Their bond is often explored, like how they support each other through difficult times. Another theme is adventure. Many fanfics send them on quests or travels to different places.
Love and affection are very common themes. Writers often explore how Tomoe and Nanami's feelings for each other develop over time, from initial attraction to deep, abiding love.
One common theme is the exploration of different power dynamics. Since Naruto has his ninja powers and Nanami has her own set of abilities, seeing how they interact in terms of power is often explored.