After losing his sister, Tor Kokonoe enrolls in the prestigious Koryo Academy, a school specializing in training students to wield Blaze, weapons that reflect their souls. Unlike others, Tor's Blaze manifests as a shield, challenging his combat skills. To overcome this, he enters the Duo system, pairing up with Julie Sigtuna, a unique student from Scandinavia with unprecedented powers and a shared desire for vengeance.