Reverse Harem in another world (Understand writing and editing)

She had been just a girl who had recently made her debut, excited for the future ahead. Tragically, the celebration was cut short by an accident that took her life. At first, she felt sorrow, but soon a new kind of fear gripped her as she realized she had awakened inside a story. Not just any story, but a BL (Boys' Love) narrative where she was cast as the step-sister of the protagonist. She had always enjoyed reading stories like this but had never imagined being part of one.

Her role in this world, however, was more than just being a supporting character. She was supposed to become an obstacle, someone destined to cause harm. But that wasn't what she wanted. No, she was determined to rewrite her fate. There had to be a way to have a nicer story, to avoid the dark path laid out for her. Yet, despite her resolve to change things, something strange was happening with the men around her.

Why did they lock her up, as if afraid she might run away? Why did her step-brother stare at her with those intense, red eyes, as if he was hiding something?