To save her critically ill sister, the ordinary girl Grace, driven to desperation, is forced to sign an absurd "fake fiancée" contract with Selena, the powerful and wealthy female CEO of a multi-billion dollar conglomerate, becoming Selena's kept woman under her absolute control. Under the oppression of money and power, Grace initially believes it's just a sham transaction, but she gradually discovers Selena's suffocating obsession and morbid possessiveness. From domineering acquisition and relentless surveillance to Selena taking a fatal bullet for her and even abandoning her entire business empire, Selena's mad love leaves Grace with nowhere to escape. When the cruel truth is revealed, it turns out the two had already forged an unbreakable bond three years earlier on a rainy night. Ultimately, this dangerous and forbidden game takes a dramatic turn: the once-arrogant underworld queen willingly dons the collar, kneels at Grace's feet, and imprisons herself forever in a cage called "love."
