After the Tower's sudden appearance, those who sought to pursue their personal values began to inhabit it, becoming known as "hunters." While everyone had their own goals, only a select few were acknowledged by the mysterious structure and granted powerful skills. Kim Gong-Ja, a weak F-Class hunter devoid of any skills, envies those blessed by the Tower. One day, allowing his jealousy to take over, Gong-Ja abruptly acquires an S-Class skill that enables him to copy another person's skill—after they kill him. Sooner than he would like, Gong-Ja tests his newly acquired ability on the legendary hunter known as the Flame Emperor. As he is dying, Gong-Ja learns the evil truth about the man he once admired most. Upon receiving another potent skill that allows him to revive and go back in time by 24 hours, Gong-Ja devises a plan to travel 11 years into the past to eliminate the Flame Emperor and cement himself as the world's best hunter.