Ten-year-old Aurora asks her hitman neighbor to kill the monster under her bed that she claims ate her family. To protect her, he must battle an onslaught of assassins while accepting that some monsters are real.

The film follows the unusual fate of Shanshan and Lang, a Chinese brother and sister living in Hungary. After a mysterious accident, their souls become trapped within a single body. As their goals and intentions prove to be fundamentally opposed, their childish quarrels gradually escalate into a life-and-death struggle.