One idea could be Draco being sorted into a different house by mistake. Maybe the Sorting Hat has a moment of confusion and puts him in Hufflepuff. This would lead to him having to adjust to the very different values and atmosphere of that house, and it could be a journey of self - discovery as he realizes there's more to life at Hogwarts than just the Slytherin way.
One plot idea could be that Draco is chained in the Hogwarts dungeons due to a false accusation. Harry, against his better judgment, decides to investigate and ends up finding out the real culprit while also learning more about Draco's complex personality. Another idea is that Draco is chained as part of a dark magic experiment gone wrong, and Hermione uses her vast knowledge to try and break the chains, leading to an unlikely alliance between them. A third plot could be that Draco chains himself as a form of self - punishment for his family's actions, and a new student at Hogwarts helps him come to terms with his past and break free from his self - imposed chains.
One plot idea could be Draco dealing with the social stigma within Hogwarts. He might struggle to hide his condition while also trying to continue his studies. Another could be his relationship with other characters changing. For example, his former rivals might show unexpected kindness or newfound respect. Also, a plot could revolve around the mystery of how this happened in the wizarding world where such things are rare.
One idea could be that Draco is jailed due to false accusations and while in jail, he discovers a magical collar that has a connection to Hogwarts. Maybe it was a forgotten relic. The collar could give him special powers or knowledge related to the secrets of Hogwarts. Another plot could involve Draco being jailed by Hogwarts authorities for a prank gone wrong with the collar being the key to his redemption as it helps him right his wrongs.
One idea could be Naruto being a transfer student to Hogwarts. He might use his ninja skills in the wizarding world, like using his speed to be great at Quidditch. Another could be that Naruto discovers he has magical powers in addition to his chakra, and he has to learn to balance both. And perhaps he makes friends with Harry Potter and they teach each other their unique skills.
A plot could involve a group of Hogwarts students accidentally ending up at Ilvermorny and having to adapt to the new school's rules and culture while also trying to find their way back home. It would be a story of discovery and friendship as they interact with the Ilvermorny students.
An OC could be a Muggle - born with a very special family heirloom that turns out to have magical properties once they arrive at Hogwarts. This heirloom could be the key to solving an ancient mystery within the castle walls, like a hidden chamber or a long - forgotten spell.
Well, perhaps in the fanfiction, Hermione transfers to Hogwarts because her family has to move for some Muggle - related reason. Once at Hogwarts, she could find that the Hogwarts library has some books that were banned at her old school. This could lead her on a quest to study those books and uncover secrets that not only help her in her studies but also in solving a mystery that has been plaguing Hogwarts for years.
Another plot could involve the Marauders getting involved in a mystery that is plaguing Hogwarts in the present day. They use their old - school pranking skills and knowledge of the castle's secrets to solve it. They might have to team up with some of the current Gryffindor students who remind them of themselves when they were young.
A possible plot could involve a Hogwarts teacher from the past crossing over to the present day Hogwarts in a fanfiction. This could lead to interesting clashes between old and new teaching methods. Or perhaps a crossover with a character from a fairy - tale world. The teacher could help the fairy - tale character understand the more complex magic of Hogwarts.
Well, perhaps in this fanfiction, Fred and Hermione could be paired up for a special assignment by a professor. They start off not getting along because of their different personalities, but as they work together, they realize they have more in common than they thought. For example, they both have a strong sense of loyalty, Fred to his family and Hermione to her friends. They could end up using their combined skills to save a part of Hogwarts from a magical threat.