Hajime Nagumo, an ordinary high school student, is transported to a fantasy world along with his classmates as part of a summoning ritual to save the kingdom of Tortus from demonic forces. While his peers receive powerful combat-related abilities, Hajime is granted the seemingly weak skill of transmutation, which allows him to manipulate materials. Initially dismissed as useless, Hajime is relegated to a support role, but his life takes a drastic turn during a dungeon expedition. Betrayed by a classmate and left for dead in the depths of the Orcus Labyrinth, Hajime undergoes a harrowing transformation. Faced with monstrous creatures and near-death experiences, he resolves to survive at any cost, using his transmutation ability to craft weapons and tools. Through sheer determination and ingenuity, he evolves into a ruthless and powerful fighter.

Emerging from the labyrinth, Hajime is no longer the same person. His once-kind demeanor has hardened, and he is driven by a singular goal: to return to his original world. Along the way, he forms bonds with several companions, including Yue, a vampire princess he rescues from imprisonment in the labyrinth. Yue becomes his closest ally and romantic interest, sharing his resolve to defy the world’s oppressive forces. Other key allies include Shea Haulia, a rabbit-eared beast girl with immense physical strength, and Tio Klarus, a dragon-woman with a penchant for masochistic humor. Together, they navigate a world filled with political intrigue, ancient secrets, and powerful adversaries, including the demon army and the gods who orchestrated the summoning of Hajime and his classmates.

The narrative explores themes of survival, betrayal, and the moral complexities of wielding power. Hajime’s journey is marked by his struggle to reconcile his humanity with the ruthless pragmatism required to survive in a hostile world. His classmates, who initially viewed him as weak, are forced to confront their own prejudices and the consequences of their actions as they cross paths with him again. The series balances action-packed battles with moments of character development, particularly in Hajime’s relationships with his companions. The overarching plot delves into the mysteries of the summoned heroes’ roles, the true nature of the gods, and the ultimate purpose behind the summoning ritual. Through its blend of fantasy, action, and character-driven storytelling, the series presents a tale of resilience and transformation in a world where strength is often the only currency.