Jishou Akuyaku Reijou na Konyakusha no Kansatsu Kiroku.

Bertia is reincarnated into her favorite otome game—not as the heroine, but as the villainess engaged to the perfect Crown Prince Cecil! Fully aware that her role is to sabotage his future romance, she’s determined to bloom as a wicked flower and wither away according to the story. But no matter how hard she tries to scheme, her “evil” plans only make her more endearing!