A plot could involve the reader being from the 'normal' world but having a strange connection to the afterlife. Beetlejuice senses this and tries to use the reader to his advantage, but ends up falling in love instead. Or perhaps the reader is an artist who can bring Beetlejuice's wildest nightmares or dreams to life on canvas, and he becomes obsessed with having the reader create more for him.
Well, the reader could be a time - traveler who gets stuck in Beetlejuice's time and place. Beetlejuice initially wants to scare the reader away but as they interact more, he starts to protect the reader from other spooky threats. Also, the reader could be a magician's apprentice who accidentally casts a spell that binds them to Beetlejuice, leading to a series of chaotic and comical adventures together.
One idea could be that the reader is a new resident in the haunted house where Beetlejuice lurks. They accidentally summon him while trying to fix up the old place. Another could be that the reader is a medium who can see Beetlejuice clearly and they form an unlikely friendship. Maybe the reader is a lost soul like Beetlejuice and they find common ground in their otherworldly existence.
In the fanfiction, a possible plot could be that Beetlejuice has a bet with another character that he can make Adam do something really out of character, like break a major rule in the afterlife. As Beetlejuice tries to get Adam to do this, Adam starts to learn more about himself and his own capabilities. Another idea is that there is a magical object in the musical world that Beetlejuice and Adam both want for different reasons. They start off as rivals for it but then realize they can achieve more by working together. And, there could be a plot where Adam gets lost in a strange part of the afterlife and Beetlejuice has to find him, during which they both grow as characters.
Perhaps a plot where Lydia and Beetlejuice accidentally swap personalities. This would lead to all sorts of comical and spooky situations. Beetlejuice in Lydia's body would have to deal with school and her family, while Lydia in Beetlejuice's body would have to handle the chaos of the Netherworld. They then have to find a way to switch back before it's too late.
A plot could involve the reader being a healer of sorts. Flowey, being curious, approaches the reader. As they interact, the reader starts to show Flowey kindness that he's not used to. This kindness begins to thaw his cold, calculating nature. They could then go on adventures together in the Underground, with Flowey slowly becoming more protective of the reader. Also, the reader could introduce Flowey to new concepts like friendship and self - sacrifice, which would be a huge change for him.
One plot idea could be that the reader is a new ninja in the village and Sasuke is assigned to train them. Through the training sessions, they start to understand each other better and develop feelings. Another could be that the reader has a special power that Sasuke needs to help him in his quest for revenge, and as they work together, love blossoms.
One plot idea could be the reader being a new hunter who catches Hisoka's attention during the Hunter Exam. Hisoka decides to 'mentor' the reader in his own twisted way, leading to a series of dangerous and exciting adventures.
Another plot could be that the reader is a journalist investigating the strange disappearances around an old, abandoned studio rumored to be haunted by Bendy. As the reader delves deeper, they encounter Bendy and instead of being afraid, they start to see the misunderstood side of him. This leads to a relationship where the reader tries to tell Bendy's story to the outside world and protect him from those who would do him harm.
Well, a plot could involve the reader being a bit of a troublemaker in the village. But Krampus, rather than just coming to punish, he wants to reform the reader. He takes the reader on a journey through the shadowy parts of the forest, showing the reader the spirits of those who were truly bad. This makes the reader realize their own actions are not as bad as they thought and they start to change for the better. Also, the reader could be an artist who tries to capture Krampus' essence in a painting, and this draws Krampus to the reader in a curious way.
Another interesting plot could be that the reader is a time - traveler from the future. They come to Arendelle during Elsa's reign and know about all the events that are going to happen. The reader tries to help Elsa avoid some of the hardships she will face in the future, but in doing so, they accidentally change the course of history. This creates a complex situation where Elsa and the reader have to work together to set things right while also dealing with their growing feelings for each other.
One idea could be the reader is a scientist tasked with studying SCP 682. The reader tries to find a way to communicate with it in a non - violent way. At first, SCP 682 is hostile, but gradually, through the reader's persistent efforts, it starts to show a bit of curiosity towards the reader.
One idea could be that the reader is a detective trying to solve the mystery of Chucky's murders and ends up in a strange psychological battle with him. Another could be that the reader is a dollmaker who discovers Chucky's true nature and has to decide whether to help him or stop him. Or perhaps the reader is a psychic who can communicate with Chucky on a spiritual level and tries to exorcise his evil.