There could be a fanfiction where Tsukune and Moka accidentally switch bodies. This would lead to a lot of comical situations as they try to adapt to each other's lives. Moka in Tsukune's body would have to deal with human school life and Tsukune in Moka's body would have to handle the vampire society. Additionally, a plot about a mysterious prophecy that involves both of them and their fates being intertwined with the future of the vampire - human relations could be really engaging.
One plot idea could be Tsukune's further exploration of his unique powers in the Rosario Vampire world. He might encounter a new type of enemy that challenges his abilities in ways he hasn't faced before. Another could be a love triangle involving Tsukune, Moka, and another character, creating a lot of drama and tension. Maybe Tsukune has to go on a quest to find a lost artifact that has significance in the vampire world, and along the way he discovers more about his own heritage.
One plot idea could be that Vampire Tsukune and Inner Moka have to team up to fight a new and powerful enemy that threatens the entire monster school. They start to train together and during this time, they discover new powers within themselves and also grow closer on an emotional level.
Kurumu would be a great character to include. She has a crush on Tsukune and her jealousy towards Moka could add some interesting drama to the side story. Also, Mizore, with her cold exterior but warm heart towards Tsukune, could bring in some unique interactions. Gin, being a werewolf, could also be included as he has an uneasy relationship with the vampires, which could create tension and conflict in the side story.
There could be a fanfiction where Tsukune, after fully embracing his vampire side, has to protect Moka from an ancient vampire threat. In this story, they might have to use their combined strength and love for each other to survive. The details of their battles and how they grow closer during the process can be really engaging.
A cool plot could be that a powerful vampire targets Naruto because of his unique chakra. Shinso gets involved as he senses something is wrong with Naruto. They discover that the vampire wants to use Naruto's chakra to break a curse on their clan. Shinso and Naruto must decide whether to help the vampire or fight against it.
One idea could be Tsukune and Inner Moka going on a magical adventure in a hidden realm. They might encounter strange creatures and have to work together to overcome obstacles. Another plot could be a mystery where they try to solve a strange occurrence in their school that seems to be related to the supernatural world they inhabit. And perhaps a plot where they get lost in time and have to find their way back while also dealing with their feelings for each other.
Love is also a frequent theme. Tsukune may find love within the vampire community or have to deal with his previous human relationships while being a vampire. Sometimes it's a love triangle between a human, Tsukune as a vampire, and another vampire. This adds a lot of drama and emotional depth to the fanfictions. There are also themes of acceptance, both Tsukune accepting his new vampire self and the other characters accepting him for who he has become.
Well, in Vampire Tsukune x Moka fanfiction, one common aspect is the exploration of their powers. Tsukune, as a vampire, has newfound abilities that he has to learn to control, and Moka is there to support him. Their relationship might also be depicted as a sort of forbidden love, especially if there are different vampire clans or factions involved. It adds an element of drama to the story. Sometimes, the fanfiction might focus on how they protect each other in dangerous situations, which really showcases their deep bond.
Tsukune himself is quite interesting. He's a human in a world full of vampires, which makes him an outlier. His journey of adapting to this new world and developing his powers is always engaging. Moka is also a great character. Her dual personality, with the sweet outer self and the more powerful vampire self, adds a lot of depth. Inner Moka especially is a force to be reckoned with. And then there's Kurumu, the succubus. Her pursuit of Tsukune in the fanfiction can lead to some really fun and flirty storylines.
There are also fanfictions that focus on the backstories of Tsukune and Moka. Maybe exploring Moka's past as a vampire, her family history, and how Tsukune fits into all of that. Or looking at Tsukune's life before coming to the school and how it has influenced his relationship with Moka.