In the late Joseon Dynasty, a female swordswoman named ‘Araci’ who hunted ghosts and protected the world succeeds in sealing away a giant evil spirit called ‘Eoduksini’, a being that grows stronger by feeding on human greed. However, peace is short-lived. Someone breaks the seal of Bongguham, and Araci’s soul becomes trapped inside her sword while time continues to pass. In Seoul, 2025, a YouTuber named ‘Kangmu’, who dreams of turning his life around through ghost-related content, pulls out an old, abandoned sword. At that moment, Araci awakens—and she possesses Kangmu’s body, beginning to fight against supernatural beings that deceive and corrupt the world.