I'm not sure specifically as there could be many different plots in a fanfic about them. It might involve their relationship developing, perhaps going through some sort of adventure or emotional journey together.
Senjoughara and Araragi are the main characters in this fanfic. Senjoughara might bring her own charm and strong - willed personality to the story, while Araragi with his own set of traits, and together they form the core of the narrative.
One common theme is self - discovery. Both characters are on a journey of understanding themselves better, and their relationship often serves as a catalyst for that. For example, in many fanfictions, Araragi realizes new aspects of his personality through his interactions with Senjougahara.
One common theme is the exploration of their complex relationship. Given Shinobu's vampiric nature and Araragi's human - turned - vampire nature in a way, their relationship is full of power dynamics, loyalty, and a strange form of mutual dependence.
One interesting plot could be a story where Senjougahara and Araragi go on a mysterious adventure together. They might encounter some supernatural beings and have to rely on their bond to overcome the challenges. This could deepen their relationship in unexpected ways within the context of the fanfiction.
A common theme is the power dynamic between them. Given Shinobu's powerful vampire nature and Araragi's somewhat normal yet complex character, their relationship often plays with who has more influence at different times.
First, you need to understand the characters well. Know their personalities, quirks, and how they interact in the original work. Then, come up with a unique plot that fits their relationship. For example, you could base it on a particular event from the original story and expand on it.
One great piece of araragi x senjougahara fanfiction is 'A Tale of Two Hearts'. It beautifully captures their complex relationship and the unique bond they share. The author does an amazing job of portraying their personalities as we know them from the original work, while also adding new and interesting twists to their story.
There's also 'The Unspoken Understanding'. In this fanfiction, the author focuses on the silent communication between Araragi and Shinobu. It shows how they can understand each other without many words, and it's a really interesting take on their relationship. It has a lot of heartwarming moments that fans of the pair will surely enjoy.