剣と魔法をデュアルに操るスクールバトル・コロシアム！剣の達人・一樹は召喚魔法を統べる神魔から謎痕を授けられたことで国立騎士学院の魔技科へと進学することになった。剣技を磨き林崎流を継ぐはずだった一樹は、女子ばかりの魔技科で魔法の特訓を始めることになり…？ 召喚魔法使いの証・聖痕を目指して剣と魔法をデュアルに操るスクールバトル・コロシアム、いま開幕——！
Parallel to our dimension is a world filled with magic, home to a host of mystical beings and fantastical powers. Humanity has learned to harness these forces and bring forth that world’s entities to do their bidding through the power of “summoners.” Our world has never been the same. Fifteen years later, Kazuki Hayashizaki is chosen as the first male summoner. His attendance in an all-female summoner class, however, is met with opposition-and none so strongly than from his own sister, the school’s most skilled swordsman. As Kazuki is torn between the way of the sword and the world of summoning, can he overcome adversity and learn to harness his new powers?
