Transmigrated into a Book as the Protagonist's Useless Little Sister

I used to be a web-novel author whose books went nowhere. By chance, I transmigrated into the world of my own novel.

Did I become the protagonist? Or the villain? Or maybe just a minor supporting character?

No, the situation was even worse than I imagined.

I became the most insignificant, overlooked character in the novel. This character is often seen as the source of motivation that helps the protagonist grow stronger, but is also his greatest burden.

A person every reader hates!

"I actually became the protagonist's younger sister..."

Still, thanks to my knowledge of the novel's plot, my useless life is about to change. I've resolved not only to become the strongest, but also to rewrite this story's terrible ending!

"I'm not letting you enter the dungeon. It's too dangerous."... But first, I have to get away from my overprotective older brother!

This novel and its characters are entirely fictional. Any resemblance to real people or events is purely coincidental. Do not imitate.