Two men have just arrived at a location known as Quindecim and are unable to remember how they got there. They are immediately greeted by a young woman who escorts them to a small bar, where a bartender awaits them. They are told that they will have to participate in a game, randomly chosen by roulette, and will be unable to leave until its completion; if they refuse, the consequences will be dire. In addition to the rules of the game, the two men are told to play as if their lives are at stake. The game that has been chosen is billiards. But there's more to it than just pocketing pool balls, as the two are about to find out the outcome could mean life or death.

Ichirou Suzuki, a programmer nearing his thirties, is drowning in work. Worn out, he eventually has a chance to catch up on sleep, only to wake up and discover himself in a fantasy RPG world, which is mashed together from the games he was debugging in reality. In this new place, he realizes that not only has his appearance changed to a younger version of himself, but his name has also changed to Satou, a nickname he used while running beta tests on games. However, before Satou can fully grasp his situation, an army of lizardmen launch an assault on him. Forced to cast a powerful spell in retaliation, Satou wipes them out completely and his level is boosted to 310, effectively maximizing his stats. Now, as a high-leveled adventurer armed with a plethora of skills and no way to return to reality, Satou sets out to explore this magical new world.

Madness and unawakening sleep, Randolph syndrome. This new illness is slowly but steadily approaching humanity, caused by the huge underground world Asylum that appeared in Antarctica. There are strange creatures different from the earth, and unknown resources. People bet their lives on the depths of the mysterious new world to get huge wealth, organizational plots, or their own ambitions. And here alone, a young man with a wish in his heart is trying to challenge the front line of Asylum. (Source: MAL News)