破局予定の悪女のはずが、冷徹公爵様が別れてくれません！ 第01巻 [Hakyoku yotei no akujo no hazu ga reitetsu koshakusama ga wakarete kuremasen vol 01]

"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…?!