The development of their relationship. If the author shows how Kazuma and Ayano gradually grow closer and the kiss is a natural culmination of their feelings, it makes for an interesting read.
Yes, there are quite a few. You can start by looking on popular fanfiction platforms like Archive of Our Own. Just search for 'kazuma ayano kiss' and you'll likely find some interesting stories. Some might be romantic, while others could be more angsty with the kiss being a significant moment in the plot.
In fanfiction, Kazuma can be seen as a bit of a risk - taker. He is not afraid to try new things or go into the unknown. Ayano is usually very empathetic. She can understand the feelings of others easily. Their relationship in fanfiction is often based on mutual respect. They support each other through different adventures and challenges, with Kazuma being more action - oriented and Ayano being more of a thinker in many of the stories.
One popular plot could be their journey in building a new life together. They might face challenges like integrating their different families or dealing with career changes. For example, Kazuma might be focused on his job while Ayano is trying to start a small business at home. Another plot could be their adventures as a married couple, traveling to new places and having unique experiences. They could also have a plot where they are expecting a baby and all the emotions and preparations that come with it.
There are quite a few out there. For example, 'Kazuma and Ayano in the Realm of Dreams'. This fanfiction dives deep into their subconscious minds and how they interact within the dream world. It's full of symbolism and interesting interpretations of their characters. Additionally, 'Kazuma and Ayano: Partners in Time' is a great read where they are sent back in time and have to figure out how to get back to their own era while also dealing with the challenges of the past.
A common theme is self - discovery. Ayano and Kazuma may discover new aspects of themselves through their interactions. Another is the theme of sacrifice. They might be willing to sacrifice for each other. Also, the theme of family can be present, either their own families or them creating a family - like bond. In some fanfics, they are like family to each other, supporting and protecting one another no matter what.
Writers often develop their characters through their daily interactions. For example, Kazuma might show his caring side when he makes breakfast for Ayano in the morning. Ayano could display her determination when she stands up for Kazuma in a social situation. They also develop through conflicts. If they have an argument about money, Kazuma might be shown as the more thrifty one while Ayano is more of a spender, which reveals more about their personalities.
Well, I know a fanfic named 'Ayano and Kazuma's Promise'. In this story, they make a promise to each other under a special circumstance, and the whole story is about how they strive to keep that promise. It has some really touching moments. And then there's 'The Hidden Feelings of Ayano and Kazuma' which delves deep into their unspoken emotions for each other. There are also some fanfics that are part of a series, like 'Ayano and Kazuma: Series One' which has multiple short stories about them.