Khun Ying Umalungsi is a princess from an old noble family. However, since her father's death, the family's fortune is in ruin and her mother decides to marry a wealthy Chinese businessman to alleviate the family's financial burden. Umalungsi is against the marriage because she doesn't understand about love and she thinks the Chinese man is beneath her. Her stepfather also wants her to marry his nephew who is despicable. She leaves her mother in order to make a living on her own instead of depending on her stepfather's charities. She decides to go to a friend that she hasn't seen in a while. On her journey, she meets Khun Mau Palod, who is seeking a teacher/nursemaid for his disabled and mute sister. Later, when Umalungsi finds out that her friend doesn't reside there anymore, Palod asks her to become his sister's teacher/nursemaid. She tells him that her name is Kroo Uma and moves to his castle, the Dark Castle...