In a world engulfed in chaos, as creatures threaten to exterminate humanity, a group of ten students and their teacher face a deadly monster attack. At the last moment, they are miraculously saved, only to be summoned to another realm of fantasy and magic!

This new world is in dire need of heroes to combat the malevolent Demon Lord, who seeks to obliterate all existence. Ruled by a Leveling System, everyone can grow stronger, but the summoned heroes possess a unique ability called Otherworldly Hero, granting them unrivaled EXP gains.

Amidst the heroes stands Dante, a slender youth with round glasses, whose skill sets him apart. Able to rewind time upon death, Dante's power proves invaluable when the school of magic where they seek refuge comes under attack, claiming their lives.

Determined to uncover the truth behind the assault, Dante embarks on a perilous mission. Who orchestrated the attack? Was it aimed at the school or the heroes themselves? And most crucially, what consequences await if he manages to stop the attack? What lied ahead?