Blazers, individuals who can manifest weapons from their soul, attend Kouryou Academy High School to develop their abilities. The students are required to pair up, with the goal of achieving the power of Absolute Duo. Tooru Kokonoe seeks to enroll in the academy to gain power after his sister and friends were killed by an unknown assailant. However, during the opening ceremony, he is forced to engage in a duel with his neighbor, and the loser will be expelled. As Tooru prepares for the fight, he manifests a shield instead of a weapon from his soul, which piques the interest of a foreign student named Julie Sigtuna.