The leading member of DWMA's internal affairs division. He is also known as B.J. (or J.B.) for short. He possesses an extremely potent Soul Perception ability which allows him to detect if people are lying, and can even sense witches' soul wavelengths when they're disguised with Soul Protect. He has an exceedingly high passion for natural coffee, despising instant coffee. He was once in a relationship with Marie Mjolnir, but broke up with her to prevent himself from seeing through her. He is brought to DWMA to search for an enemy mole, who turns out to be Justin Law, only to be murdered by him. In the anime, however, he is part of the DWMA's technological branch, and is hired to construct a device that allows Shinigami to use the magic tool "Brew" and to transform Death City into a massive robot and capture Asura.