One idea could be exploring the main character's internal struggle when she starts to have real feelings for her absolute boyfriend. She might be conflicted between the fact that he was created for her and the genuine love she's experiencing.
A third plot idea could be the introduction of another character who also has an absolute boyfriend or a similar robotic companion. The two main characters could compare their experiences, and there could be some sort of competition or friendship that develops between their robotic partners, which in turn affects the relationship of the two main characters.
Another plot could involve the absolute boyfriend getting into some sort of malfunction. This would force the main character to take care of him in a different way and perhaps learn more about his inner workings, leading to a deeper bond. For example, he might start to forget his programmed tasks but remember small details about their relationship.
Well, a great plot could involve the vampire boyfriend struggling with his bloodlust while being in a relationship with a human. For instance, he might accidentally bite his partner in a moment of weakness and then has to find a way to reverse the effects. Or perhaps he tries to introduce his human lover to his vampire family, which is full of all sorts of strange and ancient vampires with different personalities and motives.
In the fanfic, the boyfriend could be sick and sneezing a lot. The main character takes care of him, making him soup and tucking him into bed. As she does this, he realizes how much he loves her for being so caring. His sneezes become a way to show his vulnerability and her love for him deepens as she helps him get better.
A fanfiction could explore the concept of a character exchange. A Naruto character like Sasuke could be swapped into the world of Absolute Duo, and a character from Absolute Duo could be placed in the Naruto world. Then we could see how they adapt to the new environments and the new challenges they face.
A great plot could involve a character from the game trying to break free from the game's code and enter the real world. They could be on a quest to find the game creator and demand a better life for themselves and their fellow characters. This would involve a lot of action as they face obstacles both in the game world and the real world once they manage to cross over.
A really interesting plot idea could be that the rocker boyfriend has a mysterious past in the music industry. There are rumors and secrets that start to surface as his relationship with Bella grows. This could put a strain on their relationship as Bella tries to figure out who he really is. At the same time, she is also dealing with her own insecurities in this new and exciting world of rock music. Maybe she even tries to learn an instrument to be closer to him and his world.
One idea could be exploring the unspoken stories of the ranch hands. Maybe there's a hidden love affair between two of them that has to be kept secret due to the social norms of 1923. Another could be focusing on how a young character dreams of leaving the ranch and going to the big city, but faces many obstacles. And a third idea could be a mystery plot where strange things start happening on the ranch and the characters have to figure out what's going on.
One idea could be exploring the backstories of the characters more in - depth. For example, delving into how the weapons came to be in the dungeon. Another could be creating a new character that enters the dungeon and has a unique relationship with the existing characters.
One interesting concept could be exploring different relationships between the characters. For example, expanding on the friendship between the main duo in ways that the original story might not have fully delved into.
One idea could be Android 21's struggle to fit into a world that fears her. She has to prove that she's not a threat and tries to make friends. Another could be her discovery of new powers and how she uses them for good. Maybe she teams up with other characters to fight a common enemy.
One idea could be Vampirina making new friends in the human world who are initially scared but then come to understand her. For example, she could join a school club and have to prove that she's not a threat.