"Playing a greedy, man-eating villainess, but the cold-hearted Duke unexpectedly fell in love..."

Grace has been reincarnated in the world of a novel as a mob character - a promiscuous and greedy villainess! According to the story, she toyed with and then abandoned the cold-hearted Duke Zane. This results in him meeting the heroine - and if they do not meet, a war would break out and Grace would die. In order to avoid a bad ending, Grace devotes herself to being a villainous character, but due to her serious personality, she fails miserably and, on the contrary, the Duke, who is supposed to say "I will never give you anything when we break up," ends up doting on her…?!
小説の世界の、しかも当て馬以下の端役──男好きで強欲悪女グレースに転生してしまった！
物語の通りに悪女として冷徹公爵ゼインを弄んで捨て、彼がヒロインと出会うきっかけを作らないと、戦争が起きてグレースは死ぬ運命。
バッドエンド回避のため悪女キャラに徹するグレースだけど、元の真面目な性格のせいで悪女になりきれず、逆に「絶対に別れてなんかあげないよ」と振るはずの公爵様から溺愛されてしまい…!?