Jun-Woo Kim, the world's premier SSS rank genius hunter, possesses unparalleled abilities tainted by a detestable demeanor that tarnishes his name. After a fatal assault by unknown assailants, he awakens ten years in the past, determined to reclaim his hunter status. However, his past-life karma stifles his powers, necessitating a stint as a notorious 'Dungeon Cleaner'—renowned for its brutal demands. Despite facing monstrous foes, corrupt colleagues, and nepotistic superiors, Jun-Woo embarks on a chaotic journey to rectify every mess. Armed with unmatched strength and an unorthodox approach, this former hunter outshines his peers, sparking a frenzy of unconventional cleansing.