魔法剣姫アークキャリバー ～魔族降誕～

Since the ancient time, there has been the war between human and demons. Ragno, a low-ranking executive from demon world with great ambition, was given a mission to infiltrate into a school and act as a normal human teacher. His true mission is to find the "Nameless Sword" that is said to be able to grant its owner a power to control a world. On the other hand, there are young girls known as "Arch Caliber" who fight the demons with "Treasured Sword" to prevent them from getting Nameless Sword.

The girls are under an international organization that possesses the Treasure Swords "Kamyu". They fight Ragno while attending his class unknowingly. Meanwhile, another transferred student arrives to Ragno's class and she is another Arch Caliber. Although Ragno's battle is significantly tougher, the presence of the new Arch Caliber increases his chance of obtaining the Nameless Sword. However, even if he intends to fight, as a low-ranking executive, he doesn't have much fighting power.