Sim Jaehyun/ Jake

To the world, Yang Wonyoung is perfection itself—the woman they call the Angel of Korea, a model whose beauty seems almost unreal and the young CEO of a thriving company inherited after her parents' tragic death. Beneath the glamour, however, her life is painfully lonely, with only her aging grandmother offering the warmth that fame never could. Everything begins to unravel after a near-fatal accident on a rain-soaked night, where she catches only a blurred glimpse of a stranger pulling her from the water before darkness consumes her. When she awakens, an unfamiliar black cross has appeared on her wrist, a mark no doctor can explain, until sim Jaehyun burts through her hospital door. Sim Jaeyun claims the mark belongs to him and that he is a demon who lost everything the moment she survived, but Wonyoung dismisses him as delusional and refuses to believe a word he says, desperate to escape his relentless pursuit. As unsettling incidents begin to creep into her once-perfect life and the line between coincidence and nightmare starts to blur, her grandmother passes away, leaving behind not only grief but a final condition in her will: Wonyoung must marry to inherit the family empire, or watch it be torn apart by the greedy relatives waiting for her to fail. Unbeknownst to them both, the mysterious mark binding them together awakens Jaeyun's lost powers only when his hand closes around her wrist, forcing two people who despise and distrust each other into a dangerous arrangement where every step closer pulls them further into a darkness neither of them understands.