Kazuki Hayashizaki is chosen as the first male summoner. His attendance at an all-female summoner school, however, is met with opposition, especially from his own sister, who is the school's most skilled swordsman. Kazuki's sister has conflicting feelings about her little brother and can't stand his new role. Kazuki struggles against the machinations of his sister and the other students. Can he overcome adversity and learn to become a first rate summoner?