It often starts with curiosity. They meet in the Underground and are intrigued by each other. As they spend more time together, they start to trust one another. For example, Frisk might show Chara the power of kindness, and Chara might show Frisk some of the secrets of the Underground.
The relationship could start with suspicion. Frisk, coming from their own world, might not trust this new Chara right away. But as they spend time together, they could find common ground. For instance, if they both have a love for the unique monsters in their worlds. This could gradually lead to a friendship where they rely on each other.
Another theme is self - discovery. As they interact, both Chara and Frisk might learn more about themselves. For example, Chara could discover a more positive side of themselves through Frisk's influence. In some fanfics, this is a central aspect of the story, with detailed descriptions of their inner thoughts and changes.
This kind of 'fanfic' involves extremely unethical and disturbing content. Rape is a serious crime and violation of human rights in real life, and depicting it in fan - created works, even in a fictional context, is unacceptable as it promotes a negative and harmful view.
Some fanfictions focus on the relationship between Frisk and Chara in a more emotional way. For example, Chara might be haunted by their past actions, and Frisk tries to help them come to terms with it. It shows how their bond can be both complex and heart - warming, as they support each other through difficult times.
Often, there are themes related to self - discovery. Both Frisk and Chara have complex characters, and in fanfiction, they might explore their identities further in relation to each other. Also, themes of redemption can be present, especially considering Chara's somewhat controversial character in the original game. They might help each other to overcome past mistakes or traumas.
One possible interpretation could be that it's a fan - created story within the Undertale universe where the character Chara kills Frisk. It might explore dark themes, such as the corruption of a character or a deviation from the normal storyline where these two characters usually have more complex relationships that don't involve such a straightforward act of killing.
One interesting fanfic could be 'A Shared Soul'. It delves deep into how Frisk and Chara's relationship develops in a post - pacifist world. It shows how they understand each other on a deeper level and face new challenges together.
One common theme is friendship. Since Frisk and Chara are characters from the same game universe, their relationship development as friends is often explored. For example, how they support each other through various challenges in the Underground.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and you can search specifically for ones involving Female Frisk and Female Chara. Another option is FanFiction.net, which also has a wide range of works. Just use their search functions and type in the relevant characters to find some interesting reads.