"'I'll create a witch!!" In the 17th century, the German alchemist Johann Schultz successfully created a witch. He then injected that power into his own blood. In the present day, due to a scheme devised by his cousin, Yomoda Rena, Shurutsu Kenichi, a high school student and a third-generation German, secretly fights as a blood relative of "Brocken" to hunt down those who abuse the artificial witch theorem. Yet for reasons unknown, he transforms into a Magical Girl "Heroine"...?