After rescuing his former classmates from the dangers of a labyrinth—a legendary realm that bestows divine power upon those who conquer its trials—Nagumo Hajime emerges triumphant, while the fledgling heroes of Tortus confront their first significant setback. Together with his traveling allies and the fresh recruit Kaori Shirasaki, Nagumo continues his quest to master every maze and ultimately return to his native world again soon.
Meanwhile, the Earthbound heroes learn from their errors and brace for the demon army's onslaught. As the decisive clash draws near, both new and familiar foes begin to orchestrate their sinister schemes. Once again, Nagumo must demonstrate his ability to defeat the toughest adversaries while safeguarding those he cherishes most. His unwavering resolve fuels the hope of all those who depend on him.