When the protagonist reincarnates as the villainess in the world of her favorite game, Lunaria Il Fon Solfage, she also receives all of her memories. She discovers Lunaria had been condemned and ostracized by everybody in her life, ultimately leading to her taking her own life.

"Leave everything to me, Lunaria. Now that I'm you, I won't show them any mercy."

And so begins the villainess' grand revenge.

(Source: Comic Pixiv, translated)