Another theme is the 'overcoming obstacles' theme. This could be anything from dealing with the challenges of their different species (since Sans is a monster and Frisk is human) to facing external threats to their relationship within the Underground world.
The theme of 'redemption and growth' is also common. Sans may have his own past issues or flaws, and through his relationship with Frisk, he grows and changes. Similarly, Frisk might also develop in different ways as a result of their love, and this exploration of character development is a big draw in these fanfictions.
One popular theme is the 'opposites attract' concept. Sans is often depicted as laid - back and a bit of a joker, while Frisk is more determined and pure - hearted. Their differences make for an interesting dynamic in the stories.
One popular theme is redemption. Underfell Sans is often portrayed as a more 'evil' or at least morally grey character compared to the regular Sans. So, stories might focus on his journey towards redemption with Frisk's help. Another theme is survival. Given the harsh nature of the Underfell world, they often have to fight for survival together.
Their contrasting personalities make them a popular duo. Frisk is often portrayed as determined and full of hope, while Sans is more laid - back and has a sense of mystery. This contrast creates an interesting dynamic that writers love to explore in fanfiction.
Another factor is the vast and imaginative world of Undertale that they come from. Writers can explore different aspects of this world, create new scenarios, and develop their relationship in unique ways. For example, they can write about how they deal with the other monsters in the Underground or how they face challenges together.
One common theme is friendship. Despite their differences in age and experience, Baby Frisk and Sans form a strong bond. Another theme is protection. Sans often takes on the role of protecting Baby Frisk from the dangers of the Underground.
Another theme is the power of connection. In these fanfictions, the kiss represents a strong connection between them. It might be the result of shared experiences, like going through challenges together in the game world. This connection is often what drives the story forward towards the kiss moment.
One reason could be the popularity of the Undertale characters Frisk and Sans themselves. Fans love these characters and are eager to see different interpretations of their relationship. The 'flowerfell' concept also adds an interesting twist. It makes the stories more unique compared to regular Undertale fanfictions.
Another theme is discovery. Since Frisk is new to the Underswap world, they discover new things about it with Sans. Sans, in turn, discovers new aspects of himself through his interactions with Frisk. This mutual discovery is a big part of many stories.
There are many frisk and sans stories in fanfiction. Some might focus on their friendship adventures in the Underground. For example, there could be a story where they team up to solve a mystery that's been plaguing the monster community. They use their unique skills, with Frisk's determination and Sans' laid - back but clever thinking.
One common theme is adventure. Sans and Frisk often go on various adventures in the Underswap world. Another theme is friendship, showing how their relationship develops over time.
Their relationship can develop through shared responsibilities. As they prepare for the baby, they'll have to rely on each other more. Sans might take on more tasks to ease Frisk's burden, and this can strengthen their bond.