The body was possessed before the start of the novel.
Also, she, the daughter of a Count, is an extra who is bound to be murdered.

She didn't want to die like this, so she went in search of the male lead who's filled with the energy of life. The problem is that, due to his curse, he can't remember others.
As the next best solution, she even tried to target his subordinates.

"It's been long, Loreina."
What? Why does this person remember me?
It was unexpectedly due to an exception of the curse. Um. Well, I'll help you until the female lead appears. The only one who can break the curse is the female lead, so that it doesn't deviate from the original story.

...Yeah, that's exactly what she thought.

(Source: Kakao, translated)

Note: This is a promotional one-shot for the homonym novel.