Schwarz, a globally ranked professional first-person shooter player, spends his days immersed in Virtual Reality Multiple Battlefield, a VRMMOFPS teeming with advanced firearms and hostile enemies. During an ordinary match, a single misstep causes his avatar to fall through a gap in the game map. Expecting a simple respawn, Schwarz instead finds himself tumbling into an entirely new world, waking up in a realm governed by swords, sorcery, and fantasy tropes.

Now trapped in a land that operates on magic rather than hit-scan weapons and cover mechanics, Schwarz quickly realizes this is no longer a game. His digital avatar has become his true body, yet he retains full access to his inventory, including a vast arsenal of modern rifles, shotguns, explosives, and his airtight VMB combat suit. To the inhabitants of this medieval world, he appears as a magicless dud, but his firearms prove devastatingly effective against monsters and bandits who have never witnessed gunpowder. The locals soon brandish his abilities as a strange and terrifying form of magic.

The protagonist, whose real name is Ren Saito, discovers that his situation is far more complex than a simple transportation. He is not merely a player logged into a fantasy server; he is a dead man walking. It is revealed that Ren died in a freak accident in his original world, and his consciousness was transferred into his game avatar upon arrival. This explains the unsettling phenomena he experiences, such as his wounds healing on their own without explanation, reinforcing the idea that he is now an avatar operating outside the normal rules of biology.

As Schwarz struggles to survive, he uses the monster crystals dropped by his slain enemies as currency within his heads-up display, allowing him to purchase ammunition and supplies directly from his inventory interface. This creates a self-sustaining cycle of combat where he must hunt monsters to replenish his finite resources. One notable early arc sees him trapped in a monster infested tunnel system. To escape a train of pursuing creatures, he deploys poison grenades, which release a deadly gas. While the monsters succumb to the toxic fumes, Schwarz survives due to his sealed combat suit, demonstrating how his sci-fi equipment gives him an edge in a dungeon crawler scenario.

The narrative follows his pragmatic and often brutal journey as he accepts quests, explores dungeons, and engages in player versus player style battles against hostile humans. His first real PVP encounter ends in a curbstomp battle, as his gunfire outranges and outpaces any spell his opponents can cast. Despite his overwhelming firepower, the story maintains tension by highlighting his cluelessness regarding social customs and his constant fear of running out of ammunition in a world where no supply lines exist. As he searches for a way to return home or come to terms with his death, Schwarz must reconcile his video game logic with the harsh, unforgiving reality of a world where permadeath is permanent.