Kingkaew Ka Fak

Kingkaew Ka Fak (The Parasitic Jewel):
Kingkanok, a beautiful young woman, grows up in the “Ittiwat” family as the daughter of a mistress. Her father, Somyot, has three legitimate children with his wife Nanta: Piti, the flirtatious eldest son and heir to the family business; Sirivipa, the jealous middle daughter; and Jintara, the youngest, who often defends Kingkanok from being insulted as an illegitimate child.
Kingkanok’s mother, Patchanee, was Nanta’s servant. After she became pregnant with Somyot’s child and gave birth, Nanta grew increasingly hostile—especially toward Somyot’s mother, Khun Walai, who openly adored Patchanee and Kingkanok, even giving Patchanee the family’s heirloom diamond. In a fit of rage, Nanta killed Walai. Patchanee, out of gratitude for being raised by Nanta, took the blame and went to prison.
From that moment, Somyot despised Patchanee and extended that hatred to Kingkanok, treating her like a servant. Even the household maid looked down on her. Meanwhile, Patchanee, while imprisoned and secretly pregnant again with Somyot’s child, arranged for relatives Amnuay and Ruji to raise the baby.
That child, Kaewket, grows up by the seaside in a warm and loving home, becoming a spirited, tomboyish girl. She later meets Ditsatat, a heartbroken man recovering from a failed relationship with Sathita. Their first meeting is rocky after he accidentally hits her with his car. Due to a broken boat, Kaewket ends up traveling with him to a private island. There, she sees his self-destructive behavior and tries to help him recover, and love begins to grow between them.
Ditsatat brings Kaewket to Bangkok, where his mother Suphatana and younger brother Warawit grow fond of her. While shopping, Kaewket and Kingkanok unexpectedly encounter each other—and are shocked by how identical they look.
Meanwhile, Sathita moves on from Ditsatat and becomes involved with Piti, angering her brother Phanu, who is also Ditsatat’s close friend. When Phanu meets Kingkanok, he falls in love with her, but their relationship faces strong opposition—especially from Sirivipa, who also desires Phanu.
Phanu attempts to elope with Kingkanok, but Sirivipa tricks him into taking responsibility for her instead, forcing an engagement. Refusing to give up, Phanu teams up with Ditsatat and Kaewket to help Kingkanok escape—but Piti captures her and brings her back. Somyot punishes Kingkanok by imprisoning her in a basement, where Sirivipa tortures her until she begins to lose her sanity.
Determined to help, Kaewket switches places with Kingkanok and pretends to be insane inside the Ittiwat household, while Ditsatat takes the real Kingkanok away to recover. However, Piti discovers the switch and repeatedly attempts to assault Kaewket.
Kaewket later learns from an old servant that Patchanee had another child before being imprisoned. This revelation leads her to uncover the truth—that she herself is Patchanee’s daughter. She searches for her mother and, with Ditsatat’s help, finally finds her. Patchanee is reunited with Kingkanok, and Phanu asks for Kingkanok’s hand in marriage.
Fearing her crime will be exposed, Nanta poisons Somyot, leaving him paralyzed, and kills a servant to silence him. However, a confession letter exposes her, leading to her arrest.
Piti, having lost everything to gambling, kidnaps Patchanee and Kingkanok for ransom on the wedding day. Ditsatat, Phanu, and Kaewket rescue them, though Sathita is injured in the process. Piti escapes but later kidnaps Kaewket and Sathita again. This time, he is shot dead by the police. Sathita eventually reforms.
Believing Ditsatat and Sathita should reunite, Kaewket leaves for her seaside home, but Ditsatat follows her, confessing his love. They reconcile, and Kaewket finally agrees to marry him.