Charlotte is the chief of the mage hunters? Magical law enforcement? I knew the vague feeling I had last time that Shin and Alice felt like a veteran-rookie cop combo was onto something. So this really is a buddy cop story set in a world with mages and magic. Technically the two of them aren't working for law enforcement, but their vigilante actions could count as law enforcement, and now the chief of the magic police has forcibly taken them in to work for her, so that takes care of that.
Also, Charlotte is nuts.