I'm Being Raised by Villains

Neglected by her family, Cha Mi-So dreams of life in her favorite novel as the beloved main character. Then one day, she wakes up inside the novel, but as Eileen Etam, a downtrodden side character who will be kicked out of her home! To avoid further neglect, she plots to leave before that occurs. But when Erno Etam, the crazy heir to House Etam, claims that Eileen is his daughter, her plans are foiled, and Eileen finds herself in the middle of a conflict between House Etam and a cast of villains.

(Source: Tapas, edited)