After losing his younger sister Otoha, Tooru Kokonoe enrolls at Kouryou Academy to earn a Blaze, a weapon manifested from a student's own soul, and grow strong enough for revenge. His Blaze turns out to be a shield instead of a weapon, marking him an 'Irregular' among his peers, and he's paired as combat partner and roommate with Julie Sigtuna, a girl from the Scandinavian village of Gimle chasing vengeance of her own.