Ije Geuman Pahonhae Deurilgeyo

Soojin is suddenly transported into the 18-year-old body of Leah, the second female lead in her favorite web novel. As a villainess reincarnate, her mission is to avoid a terrible ending. Soojin's only option is to break off the engagement... However, Devan, her egotistical fiancee is not making this easy, not one bit.
(Source: POCKET COMICS)