In Kyo x Yuki fanfiction, 'character growth through each other' is a popular trope. They can learn from each other's strengths and weaknesses. For example, Yuki can learn from Kyo's more straightforward and passionate nature, while Kyo can learn from Yuki's calm and collected demeanor. 'Mutual understanding' is also a big one. As they start to understand each other better, they form a deeper bond. Additionally, the 'sacrifice for each other' trope can be seen. They might be willing to put themselves in harm's way to protect the other, which shows the depth of their relationship in these fan - created stories.
Fanfictions often change their relationship dynamics by exploring different emotional aspects. For example, in some, Kyo might show more vulnerability towards Yuki, which is a big shift from their initial rivalry. This can lead to Yuki being more empathetic towards Kyo. Another way is by changing the power balance. In the original, they had a certain power dynamic, but in fanfiction, it could be reversed, like Yuki being the one to physically protect Kyo instead of the other way around.
In many such fanfictions, Yuki's friends would likely launch a desperate search to find him. Kyo might put aside his differences with Yuki in order to rescue him. They would follow any leads, no matter how small. For example, if there was a witness who saw the kidnapper's vehicle, they would track it down. And Tohru would be a source of emotional support for everyone involved, constantly worried about Yuki's safety and trying to keep everyone's spirits up during the search.
It could be a jealous rival from school. Maybe someone who's envious of Yuki's popularity and good looks. This person might have snapped and decided to kidnap Yuki to teach him a lesson.
One plot idea could be that the OC is a new student at the school Yuki attends. They accidentally bump into each other in the hallway, and Yuki's polite apology makes the OC intrigued. As the story progresses, the OC discovers Yuki's secret about being a part of the Sohma family and helps him come to terms with his insecurities regarding his place in the family and among his peers.
The relationship could develop uniquely if the OC is an artist. The OC could see Yuki as a muse and start drawing him. Yuki, who is not used to being the center of someone's creative attention, becomes curious about the OC. This mutual interest in art and the OC's view of Yuki as more than just a student or a zodiac member can lead to a deep and different kind of relationship.
Friendship is another theme. The reader often becomes friends with the various members of the Sohma family. In some fics, it's about the reader bringing the family closer together through their friendship, like in 'The Reader's Bond with the Sohmas' where the reader helps heal some of the family rifts through their genuine friendship.
Definitely. The Fruits Basket manga is complete. It provided a satisfying conclusion to all the arcs and left fans with a fulfilling reading experience.