Perhaps she returns to solve a mystery that has been plaguing the wizarding world since she left. This could involve dark magic artifacts or a series of unexplained disappearances.
Harry and Ron are obvious choices. They have a long - standing friendship with Hermione, and their reunion would be filled with reminiscing and new adventures.
One possible plot could be Hermione using her intelligence to revolutionize the wizarding world's education system in her bid to take over. She might introduce new spells and magical theories that no one has thought of before.
A possible plot is that Hermione, being the book - smart witch she is, is analyzing all the details of the World Cup, and Cedric, being a popular and skilled wizard, gets involved with her when she uncovers something strange about the magical creatures used in the pre - match shows. They could end up on an adventure to ensure the safety of these creatures and the smooth running of the World Cup. It could also be that Cedric has a secret task given to him related to the World Cup, and Hermione accidentally stumbles upon it. He has to decide whether to trust her or not, and they then form an alliance to complete the task.
One interesting concept is the exploration of different magical creatures that are only briefly mentioned in the original wizarding world. For example, fanfiction might delve deeper into the lives and behaviors of thestrals. Another is the creation of new spells and how they interact with the existing magical system. It can also be interesting to see how different authors re - imagine the Hogwarts houses, perhaps by adding new traditions or changing the way students are sorted.
Another plot might involve Naruto's friends and how they react to his married status. For example, they could be teasing him or helping him out in his new married life. There could also be some comical situations like his friends trying to give him relationship advice but it ends up being more of a mess.
One interesting plot could be Mal facing her old friends who have changed in her absence. Maybe they're now involved in different schemes on the isle, and Mal has to navigate through those complex relationships while also dealing with her own growth and new values from Auradon.
Perhaps in the 'naruto returns stronger fanfiction', Naruto returns with enhanced physical abilities. He could have trained in a special place that increased his strength, speed, and stamina exponentially. For example, he might have found a way to tap into a new source of chakra that is much more powerful than the normal one. This would make his attacks more devastating and his defenses impenetrable.
One possible plot could be that Edward returns to Bella after a long self - discovery journey. He realizes that his love for her is unwavering. Another might be that he comes back to protect Bella from a new and dangerous threat in Forks.
Another plot could involve Maria's return and her interaction with Bella. This could add a new layer of tension in Bella's relationship with the Cullens. Maria might see Bella as a threat or an opportunity, depending on how the story is crafted.
One possible plot could be Sasuke returning to Sakura after a long and dangerous mission. He realizes how much he has missed her and they start to rebuild their relationship. They might go on dates and do simple things like having dinner together or taking walks in the village.