One common theme is friendship. Since they start off with some misunderstandings and conflicts, many fanfics focus on how they build a friendship over time. For example, they might have to work together to face a common enemy, and through that, they start to respect and like each other.
One popular 'naofumi x motoyasu fanfic' is 'The Unlikely Bond'. It explores their relationship in a very interesting way, showing how they overcome their differences and start to understand each other better. The character development in this fanfic is really well - done.
One common theme is redemption. Since their relationship in the original work might have some conflicts, fanfictions often explore how Motoyasu can redeem himself in Naofumi's eyes. Another theme is friendship growth, showing how they gradually become closer and trust each other more.
Yes, there are quite a few. You can start by looking on fanfiction websites like Archive of Our Own. There, you might find some interesting stories about their relationship, whether it's a friendship - centered one or something more complex. Just search for 'naofumi x motoyasu' in the search bar.
Character growth is another key feature. Naofumi may become more confident and less jaded, while Raphtalia could become more independent yet still devoted to Naofumi. In many popular fanfics, their individual character arcs are intertwined with their relationship, making the story more engaging and complex.
I'm not familiar with the 'Motoyasu Death Web Novel', so I can't say for sure who Motoyasu is. But in a web novel context, he could be a protagonist, an antagonist, or a supporting character.
Fanfiction.net is also a great place to search. It has been around for a long time and hosts a vast amount of fanfiction. Just use the search function and type in 'naofumi x queen mirelia' to see if there are any relevant stories.
There could be 'naofumi x queen mirelia fanfic' where their relationship starts as a political alliance and gradually turns into a deep emotional bond. Maybe in a story, they initially come together for the sake of their kingdoms but then discover they have more in common than they thought. They start to rely on each other not just for political reasons but also on a personal level.
Another theme is romance, of course. The relationship between Naofumi and the reader character might develop slowly over time. There could be moments of blushing, shy glances, and the gradual realization of their feelings for each other. Some fanfics might focus on the more tender, emotional side of their relationship, while others could have a bit of a love - hate dynamic at first that turns into love.
You can try some popular fanfiction websites like Archive of Our Own (AO3). There are a large number of fanfics about different pairings, and it's likely you'll find many great naofumi x raphtalia ones there. Just use the search function on the site.