Lee Oh Reum completes a tutorial quest, seemingly within a game system, and is presented with rewards. However, he's suddenly thrust into a chaotic scene where the "Black Beast" he just defeated in the tutorial has appeared in the real world. Overwhelmed and initially confused by the situation, and seeing people getting killed, he begins to recognize that the game's mechanics, like his skills, are also manifesting in reality. Realizing the connection between the game and his current dire situation, he decides he has to fight the monsters to survive.