One fateful night, Moa Son, a typical office employee, finds herself in a dungeon and transforms into a collecting hunter. Surviving a perilous encounter, she tumbles back into the dungeon but is saved by the top hunter, Jihan Seo, who binds their fates together. Now, he proposes a deal to empower her: 'Pledge to give your all in slaying every dungeon boss worldwide.' Say what?