For a child born with the Narvidal's brand, life past the age of 21 is impossible. That is the unfortunate fate of Isabelle Bilothian, the first princess in five hundred years to be born into the Bilothian royal family. However, Isabelle is special: she remembers her past life in South Korea, where she was an orphan who battled an illness before dying at a young age. Moreover, she knows exactly who she has been reborn as—a villainess from her favorite novel.

Given her knowledge of key characters and future events, Isabelle quickly avoids her first close encounter with death and wins the favor of her family. Surrounded by the warmth of familial love and loyal subjects, Isabelle uses everything at her disposal to help the world around her and make the most out of her numbered days of happiness.