One interesting storyline could be about a new student at Gotham High who discovers a secret society within the school that has ties to the city's criminal underworld. This new student then has to decide whether to expose the society or get involved with it.
One interesting storyline could be about a new student who has a unique musical talent that challenges the existing hierarchy at the school in the Dream High universe. For example, this new student might be able to combine different musical styles in a way no one has thought of before, causing a stir among the teachers and students alike.
Another storyline could involve a sports competition at Konoha High. Naruto and his friends form a team for a ninja - themed sport, like a version of capture the flag. They face challenges not only from rival teams but also from internal team conflicts, like Sasuke's initial reluctance to fully cooperate.
One interesting storyline could be about the main character exploring uncharted regions in the game world. Maybe they discover a hidden species that has unique abilities and they have to figure out how to interact with it. Another could be a fanfiction where the character forms an unexpected alliance with an enemy in the game to overcome a greater threat.
In the 'naruto gets high fanfiction', it could be that Naruto is exposed to a genjutsu that makes him feel 'high'. He might struggle to break free from it at first. As he tries to escape, he discovers new aspects of his own mental strength and also learns more about the nature of genjutsu. This experience could then make him a stronger ninja in the long run.
Some Gotham fanfictions might take a different turn and be set in an alternate universe. In this kind of story, the characters could have different personalities or occupations. For instance, Bruce Wayne could be a detective instead of Batman, and the whole dynamic of Gotham would be changed accordingly.
One interesting storyline could be Alucard forming an unexpected alliance with the main characters in High School DxD. Maybe he uses his unique powers to help them in a battle against a common enemy.
One interesting storyline could be that Naruto and his friends are transported to the Monster High world. They could team up with the Monster High characters to face a common threat. For example, a powerful demon that is causing chaos in both the Ninja world and the Monster High world. Another could be a cultural exchange where Naruto shows the Monster High students his ninja skills and they in turn show him their unique monster abilities.
One interesting storyline could be about Naruto forming an unlikely friendship with a shy and studious character at the ninja high school. They help each other grow, Naruto teaching the other about courage and the shy character helping Naruto with his studies.
Some fanfictions might explore the idea of the characters having different clubs in high school. For instance, Naruto could start a ramen - eating club, which is actually a front for a secret ninja training club. Sakura might be in the medical club, learning advanced first - aid techniques that are also useful in ninja battles. And then there could be a big mystery in the school, like someone is using forbidden jutsu on other students, and the main characters have to figure out who it is while also dealing with their normal high school problems like exams and relationships.
One interesting storyline could be Fem Luffy joining the high school's sports team. Since Luffy is known for his physical strength and determination in the original story, as a female in high school, she could be the star athlete. Maybe she overcomes gender biases in sports at school. For example, some might think that certain sports are not for girls, but she proves them wrong with her skills and tenacity.