Sierra on Strike!(2022)

Sihanburaseo Paeopaenneunde

As high society's most eligible lady, Sierra Fernein did whatever it took to please her family, despite their flagrant disregard for her. But upon discovering she has only a month left to live, she decides to go on strike from being a prim and proper lady and live life on her own terms. Shedding the Fernein name, she declares war on anyone who dares get in her way, including her family and a few pesky admirers. But with just 30 days left, can Sierra finally enjoy the life of her dreams?

(Source: Tapas)

Note: Includes 19 extra chapters.