You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). These platforms have a large collection of fanfictions from various fandoms, including Rosario Vampire. Just use the search bar and type in 'Rosario Vampire Tsukune and Tsurara' to see the available stories.
One popular theme is romance. Given the relationship between Tsukune and the other characters in the Rosario Vampire world, it's common to see fanfictions exploring the romantic relationship between Tsukune and Tsurara. It could be about how they first fall in love or overcome obstacles in their relationship.
First, know the characters well. Tsukune is a complex character with his own growth arc. Make sure to stay true to his personality. Also, understand the world of Rosario Vampire, like the different monster species and their cultures. Then, come up with an interesting plot. It could be a new adventure for Tsukune or a different take on his relationships.
One great Rosario Vampire Tsurara fanfiction is 'Tsurara's Hidden Adventure'. It delves into a side of Tsurara that we don't often see in the original work. The author does an amazing job of portraying her emotions and her relationships with other characters in a new light.
Tsukune's vampire form in fanfiction can vary greatly. Some authors might focus on the emotional aspect of him dealing with this new side of himself. He could struggle with the urge to feed on blood, or he might embrace it as a part of his new identity. Additionally, his relationships with other characters, especially Moka, can be significantly affected by his vampire form.
A possible fanfiction could focus on a love triangle between Kurumu, Tsukune and another character. Kurumu is deeply in love with Tsukune, but Tsukune is conflicted as he has feelings for Kurumu but also has responsibilities towards others. This would lead to a lot of emotional drama and interesting character interactions.
One great Tsukune and Kurumu fanfiction could be a story where they go on a magical adventure together outside of the school. They might face some new and powerful enemies that test their relationship and skills.
Fanfiction could also center around Mizore and Tsukune training together. Since they both have different powers, they could learn from each other. Tsukune could teach Mizore about human resilience and determination, while Mizore could show Tsukune how to better control his powers, especially when it comes to the more vampiric aspects. Their training sessions could be filled with both comical and intense moments.
One possible fanfiction could be about Mizore and Tsukune going on an adventure together in the world of Rosario Vampire. Maybe they have to face a new kind of supernatural threat that has emerged in the school. They could use their unique abilities, Mizore's ice powers and Tsukune's growing vampire - human hybrid powers, to combat this threat and protect their friends.
One possible fanfiction could be about Nekonome and Tsukune going on a secret adventure in the school grounds. Maybe they discover a hidden passage that leads to a place full of magical artifacts. Nekonome's feline instincts could help them navigate through the dangerous parts while Tsukune's growing powers could be used to protect them from any threats.