During 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, as a result of a scheme created by his cousin, Yomoda Rena, Shurutsu Kenichi, a high school student and a third generation German, fights on secretly as a blood relative of "Brocken," all in order to hunt down those who abuse the artificial witch theorem. Yet for reasons unknown, he transforms into a Magical Girl "Heroine"...?
(Source: Operation Boredom)
Volume 1: Nurse Assault!
Volume 4: Bloomed in Action
Brocken Blood was initially published as a one-shot in the February 2004 issue of Young King Ours, and then the second one-shot in the Young King Bessatsu Kingdom in 2004. Official serialization began two years later in the third 2006 issue of Young King. In 2009, serialization switched to Young King Ours.