Ryan, a 27-year-old American, was on his usual morning run through a Midwest forest when, without warning, he was struck by a mysterious magical orb that ripped him from his world and hurled him into an unknown land. There, he was captured by a tribe of Dark Elves, who had summoned him along with another unfortunate soul: Hiro, a nervous Japanese teenager obsessed with otaku culture, who believes he’s the protagonist of his own fantasy.
For Ryan, Hiro is just another problem in a list that keeps getting longer. Captured by the Dark Elves, both are forced to hunt monsters, absorbing the mana released by their kills — a process with increasingly alarming consequences.
But the situation takes an even deadlier turn when the "Three Divines," a fearsome holy group determined to eradicate all so-called "subspecies," launch an attack on the tribe. Ryan barely escapes with his life, only to be hunted by goblins and driven into the depths of an unknown labyrinth.
However, the true nightmare is just beginning: the mana absorbed from humans and monsters alike starts to transform his body in unpredictable ways. And, to his horror —or perhaps his salvation— Ryan begins to change into a Dark Elf… or rather, a Dark Elf woman? Along with this transformation, he awakens an extraordinary ability: the power to heal anything.