A Chu, a cannon-fodder ghost from an illustrated storybook, is trapped in Youlan Shrine. She unexpectedly encounters Si Chengyang, an immortal demon lord who cannot die. Hiding on a roof beam, A Chu secretly watches as Si Chengyang eliminates one after another of the 'heroines' who come to win him over, until he catches her in the act. To save her life, A Chu gives him the tiny amount of eerie energy she possesses, only to discover that she can heal his injuries and weaken the Heavenly Dao's restraints. She becomes the key to his breaking free from the fate imposed upon him. The two set off together to roam the martial world. Their mutual threats gradually turn into flirtation, and amid playful banter and teasing, tender feelings begin to grow as they slowly uncover the secrets hidden within each other.