A possible plot for 'naruto high school harem fanfiction' could be that Naruto is given a special project in high school where he has to work with a group of girls. As they work together, the girls start to develop feelings for Naruto. There could be drama within the group as some girls are more forward in their feelings while others are shy. And Naruto, being his oblivious self at first, slowly starts to realize the situation and has to figure out how to handle all these new emotions and relationships.
One plot idea could be the characters from Naruto finding themselves in the world of High School DxD and having to adapt to the different rules and powers there. They might form alliances with the characters from DxD to face a common enemy.
One plot idea could be that Naruto, with his ninja skills, gets transferred to the High School DxD world. He might accidentally join the Occult Research Club and use his Rasengan to defend the club from various threats. His positive attitude and never - give - up spirit could inspire the DxD characters and also attract the girls in the harem, leading to some comical and action - packed situations.
One idea could be a sports competition at the high school where Naruto and his friends compete in a ninja - themed track and field event. Another could be a school dance where there are some unexpected alliances and rivalries revealed. Maybe a new student arrives who has a mysterious past related to the shinobi world.
Another plot could be that there is a threat to both the Naruto world and Monster High. Naruto teams up with the Monster High crew, and during their adventures, some of the female characters start to develop feelings for him. He is constantly saving them with his Rasengan and other jutsu, and his kind heart makes them fall for him one by one, creating a harem.
Maybe Ash is a transfer student to Harem High School. At first, he's a bit of an outcast because of his different upbringing in the Pokémon world. But as time goes on, his kindness and courage start to draw the attention of different students. For example, the school athlete might be impressed by his physical endurance from all his Pokémon adventures, and the smartest student in the class could be intrigued by the knowledge he has of different Pokémon species. This creates a diverse group of characters that form his 'harem' in a sense.
One plot idea could be that Naruto is summoned to the High School DxD world by a powerful magic user who mistakes him for a powerful demon. Once there, Naruto has to prove that he is not a threat while also trying to find a way back home. Along the way, he befriends some of the students at the school and helps them with their own problems, like protecting the school from a sudden attack by a group of rogue devils.
A plot idea could be that some of the devils in High School DxD want to learn the secrets of chakra from Naruto. So they kidnap him to their world. Naruto then has to find a way to escape while also dealing with the political intrigue among the devils, angels, and fallen angels. Another idea is that Naruto's shadow clones could be mistaken for some new type of summoned creatures in the DxD world.
Well, perhaps the main character in the 'pokemon high school harem fanfic' is a trainer who has a special pokemon that can transform into different forms. The female characters in the harem are all from different pokemon battling teams. They become interested in the main character because of his unique pokemon and his kind heart. As they interact more in high school battles and training sessions, the harem dynamic develops.
Well, in high school Naruto fanfiction, a cool concept could be Naruto forming a ninja club at school. They train after school hours and enter into friendly competitions with other clubs. Or perhaps a story where Naruto discovers a hidden ninja heritage in his high school, like an old dojo or a secret scroll left by a former ninja. Also, a high school where the characters are all descendants of Naruto - era ninjas and they have to live up to their ancestors' legacies while dealing with normal high school stuff like exams and prom.
Well, a great plot might be that Ino is tutoring Naruto in a difficult subject like chemistry. As they study together, they start to develop feelings for each other. Also, there could be a high school play where Naruto and Ino both audition for the lead roles. There's a lot of drama and competition, but in the process, they fall for each other. And perhaps there's a mystery in the school, like something going missing from the art room, and Naruto and Ino team up to solve it, bringing them closer.