When an unprecedented catastrophe strikes, 41 students from Shiromine Academy's class 2-7 find themselves transported into a vast, magical dungeon. Armed only with Divine Protection abilities known as 'Vocations,' they must navigate to the dungeon's depths to escape—their sole chance at survival. Among them is Momokawa Kotaro, a Literature Club member and attendance number 19, burdened with the 'Shaman' vocation—a skill set fundamentally misaligned with combat. Physically unremarkable and lacking martial prowess or potent magic, Kotaro faces abandonment by his stronger classmates as they pursue their own survival. What begins as desperate cooperation transforms into something far darker. Rather than unite against a common enemy, the students become ensnared in a brutal competition where alliances shatter and murder becomes inevitable. Trust dissolves into betrayal, camaraderie into carnage. For only a chosen few can return home. This is no conventional isekai. Where others feature chosen heroes and cooperative triumphs, this world demands sacrifice and ruthlessness. Kotaro's journey through the dungeon becomes a descent into a gruesome battle royale—one where survival demands more than strength, where cunning and desperation reshape human nature itself. A tale of tragedy where the price of escape is measured in blood and broken bonds.