The story begins with Shuntaro, a young boy, finishing his character creation in the new VRMMORPG, "Eternity." He randomly receives the unique skill "Dungeon Generation" and, intrigued, decides to keep it. "Eternity" is a highly anticipated, expensive VR game that initially had only 100 beta testers. Shuntaro was fortunate enough to obtain the game through a free distribution lottery for new players. On the day of the official launch, all players, including Shuntaro and a group of three other players he observes, are thrown into the game world.
The other players are struggling with low-level "Demi-Rats," highlighting the game's intense realism and the drain on player stamina. Shuntaro, after a brief combat experience, decides to test his unique skill. As he activates "Dungeon Generation," the sky turns an ominous purple, and a massive winged dragon appears over the main city, Aristas. Simultaneously, all players' menus are forcibly opened, and a system message from "Mother AI" announces that logging out is impossible, pain settings are fixed, and resurrection is disabled. Players are told they cannot return until they destroy "him," and their third death will be their last. The game has officially become a death game.
Shuntaro awakens in a dark, stone-like structure, initially mistaking it for a dungeon generated by his skill. He checks his status and sees the same dire message from "Mother AI." Panic sets in as he realizes he cannot log out and faces permanent death. He encounters a pale, white-clad girl with horns, who is surprisingly calm. Shuntaro, overwhelmed, tries to explain their predicament, but his sudden approach startles her. Their interaction is interrupted by the arrival of several imposing figures: a butler, a giant, a silver-haired woman, and two knights. Shuntaro quickly deduces they are NPCs, but then notices their name tags read "MOB," specifically "Boss MOB." Overwhelmed by the realization that these powerful beings are enemies, he faints.
Meanwhile, in the bustling city of Aristas, approximately 350,000 players are in chaos. A young man named Wataru, who will later become the master of a major guild, rallies the panicked players. He explains basic survival mechanics, currency, and the importance of staying within the city for safety. He offers resources and guidance from his "Crest" guild, providing a glimmer of hope.
Shuntaro wakes up in a luxurious room within a massive castle. He is greeted by the white-haired girl, now identified as Bumpy, and the butler, Elrod. He is also introduced to the black-haired knight, Theodore. Shuntaro is shocked to discover that these powerful beings, along with others, are not NPCs but "Boss Mobs" and that he is somehow their "Lord." Elrod explains that Shuntaro's "Dungeon Generation" skill, which unexpectedly connected to their castle, has made him their ruler. They pledge their loyalty, acknowledging his ability to nullify their attacks and his potential to use them as materials.
In the "King's Chamber," the six Demon Lords, including Elrod, Bumpy, and Theodore, discuss Shuntaro's unexpected dominion over them. They are powerful beings, each ruling their own "world" within the castle. They are frustrated by their subjugation but are intrigued by the possibility of returning to the outside world, a long-held desire. Shuntaro, meanwhile, experiments with his "Dungeon Menu," using his skill to create a rock that destroys a chair. He then summons a slime named Puni-o. Unbeknownst to him, his "synthesis" ability, when applied to the captured mobs in the prison, transforms Puni-o into a terrifyingly powerful "Abyss Slime" with immense stats and abilities, including "Boss Trait," which halves all attacks below its level. This act of accidental creation instills a profound fear in the Demon Lords, solidifying their loyalty to Shuntaro, whom they now perceive as a being of immense, uncontrollable power.
In Aristas, players are being organized into combat and non-combat groups. Wataru and his guild are working to maintain order and provide resources. However, many skilled players, including some beta testers, are leaving the safety of the city to explore and gain advantages elsewhere. The guild faces the challenge of managing the large population and the dwindling resources.
Meanwhile, three players who left Aristas are ambushed in the Iriana Mines. One of them, Karuo, is attacked by spiders, and another, Shinta, is killed by a Player Killer (PK) named Kid. Kid, a powerful beta tester, is enraged by the death of his friends and vows revenge.
The Demon Lords, now loyal to Shuntaro, discuss their situation. They are aware of the players' struggles and the dangers of the game. Shuntaro, still somewhat naive, focuses on Puni-o's incredible growth, unaware of the fear he has instilled in the Demon Lords.
The first day in "Eternity" concludes with players on the city walls preparing for night patrols against potential "invasions" of monsters. Wataru and Alva, key figures in the Crest guild, discuss their ambitious plans to manage the player population and the challenges ahead, including the need to find players with specific unique skills. The existence of Kid, who survived a brutal PK attack, adds another layer of unease.
