One popular storyline could be Robby and Tory teaming up to face a common enemy within the karate world. Maybe an old rival from another dojo who has a vendetta against Cobra Kai. They put aside their differences and use their combined skills to protect their dojo.
In some fanfiction, Robby might develop by becoming more confident in his abilities. For example, if he's in a story where he has to lead a group of younger students, he could grow into a more responsible and self - assured person. Tory, on the other hand, could develop her softer side. Maybe she befriends someone outside of karate who helps her show more compassion.
One great 'Cobra Kai Fanfic' is 'The New Generation at Cobra Kai'. It focuses on the new students who join the dojo and how they adapt to the intense training environment. Another interesting one is 'Cobra Kai's Redemption Arc', which explores the possibility of some of the more antagonistic characters finding redemption. And 'Love in the Dojo' is a fanfic that delves into the romantic relationships that could potentially form among the characters in the Cobra Kai universe.
Cobra Kai is purely fictional. It takes the concepts and characters from the Karate Kid and builds on them in an imaginative way, rather than being rooted in real-life happenings.