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.
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.
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.
One idea could be to explore Beetlejuice's backstory in more detail. Maybe show how he became the mischievous spirit he is. Another could be a love story within the Beetlejuice musical universe, like a character falling in love with a ghost. Or perhaps a story where the characters have to deal with a new, even more powerful supernatural threat.
One idea could be a crossover where Beetlejuice accidentally ends up in the wizarding world of Harry Potter. Maybe he tries to cause chaos in Hogwarts but is thwarted by the students and teachers. Another could be a story where a Harry Potter character, like Hermione, summons Beetlejuice while researching dark magic or strange entities, and then has to deal with the consequences of his presence. A third idea might be that Beetlejuice uses his powers to disguise himself as a Hogwarts student to play pranks on everyone.
The reader could be a lost traveler who stumbles upon Dracula's castle during a storm. Dracula offers shelter, but the reader soon realizes that there's something not quite right. As time passes, the reader discovers Dracula's loneliness and begins to feel sympathy for him. This could lead to a friendship or more, as the reader tries to bring some light into Dracula's dark existence.
A plot could involve Lydia inviting Beetlejuice to a human party as her plus - one. Beetlejuice has no idea how to act at a normal human gathering and causes all sorts of mayhem, from scaring the guests to turning the party food into strange and otherworldly delicacies. Meanwhile, Lydia has to keep him in check while also trying to show her friends that he's not as bad as he seems. Or perhaps there's a new ghostly threat in the afterlife that only Lydia and Beetlejuice can stop together. They have to put aside their differences and work as a team, which is difficult given Beetlejuice's self - centered nature.
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 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.
One idea could be that the reader is a scientist who discovers a way to communicate with gremlins. The gremlins are initially suspicious but as the reader shows no harm, they start to cooperate. Together, they try to solve a mystery in the gremlin's underground lair that is affecting both their worlds.
One idea could be a reader who suddenly finds themselves in the Pokemon world during a big Pokemon tournament. They have to quickly learn about the different Pokemon types and battle strategies to compete. Another plot could involve the reader being a Pokemon trainer from a different dimension where Pokemon have unique abilities not seen in the normal Pokemon world. They then have to adapt and use these new abilities to their advantage while making friends and facing rivals.