In a fanfiction, the main character could find an old list of the 100 things that their parents or an older sibling had made. They then decide to redo the list in their own way, adding new elements and skipping some that are no longer relevant. This journey of rediscovery and self - expression through the list could be the central plot.
In a high school fanfiction, perhaps Itachi is a new transfer student. Sakura, being the curious and friendly girl she is, decides to befriend him. They end up getting paired for a school project. At first, Itachi is quiet and reserved, but as they work together, Sakura discovers his hidden depths and he starts to open up to her more. This could create a really interesting dynamic between them.
One idea could be that Jack is the new student in high school and Elsa is the popular but reserved girl. They get paired for a science project and slowly discover they have a lot in common, like their love for winter and their insecurities. They start to bond over their shared experiences and develop a friendship that might turn into something more.
Another possibility is that they are both part of a high - school club. For example, a dueling club. Yusei is already really good at dueling, and Akiza is new to it. Yusei helps Akiza improve her skills. During this process, there's some light - hearted banter and a bit of a competitive edge between them. As they spend more time together in the club, feelings start to develop that are more than just friendship.
One idea could be that Percy and Annabeth are new students at a high school filled with mythological secrets. They have to hide their demigod status while also dealing with normal high school problems like exams and bullies. Maybe they join the school's swim team and debate club respectively, which could lead to some interesting interactions.
Maybe they are new students at the same high school. Percy, being the son of Poseidon, has some strange things happen around him. Jason, from his own background, tries to figure out what's going on with Percy and they end up becoming friends.
One idea could be that Ben Tennyson somehow gets transferred to the world of High School DxD. He has to keep his alien forms a secret while dealing with the devils, angels, and fallen angels in the school. Maybe his Omnitrix could be misinterpreted as some kind of powerful devil device.
One idea could be a story where Gaara travels to different hidden villages in the Naruto world to learn new sand-based jutsu techniques. He meets various characters along the way and has to overcome challenges that test his newfound skills and his friendship with Naruto.
One idea could be that they compete in various school competitions like academic decathlon or sports events, always trying to outdo each other. For example, in a science fair, Percy might do a project on underwater ecosystems because of his love for the water, while Annabeth does something related to architecture. Their rivalry makes them both push harder and come up with more creative ideas.
One idea could be that Naruto is somehow transported to the world of High School DxD. He could use his ninja skills, like shadow clones, in the battles against the devils and fallen angels in that universe. Maybe he'd form an alliance with Issei and his group, teaching them some unique ninja techniques.
One idea could be a story where Naruto and Natsu from Fairy Tail are new exchange students in a high school. They quickly become friends due to their similar energetic and fearless personalities. They form a club that combines ninja skills and magic, much to the confusion and awe of their classmates.