This new show from Sunrise is set in present-day Tokyo. In this world, many "Craft users" or "witches" are considered threats to mankind. For this reason, they have been hunted down by an organization called Solomon for centuries. STNJ is Solomon's Japan branch, and they have recently lost one of their crack witch hunters who perished during a hunt. As her replacement, a young witch hunter is transferred to STNJ. Her name is Robin. She was raised and trained to be a witch hunter in a monastery in Rome by a priest who is also a legendary exorcist. Witch hunters themselves possess some Craft powers, and Robin's special ability is to control fire. At STNJ, She is assigned to work with a unit led by witch-hating team leader named Amon whose mother - we learn soon enough - was a witch.

Unlike Solomon's other branches, STNJ prefers to capture witches instead of killing them. The hunters often use a substance called the "Orbo" to contain and neutralize the witches' powers, but Robin prefers not to use it either. As she starts working, questions pop up in her mind as to the reasons behind the historical conflict between humans and witches. And what about the other organization called the "Factory" where the captured witches are purportedly taken to?
What are they and Solomon exactly up to? These and many other questions arise during the course of this series that treats each episode as an important ground for character and story development.

First-time director Murase Shuko is well known as the character designer and/or original writer for such shows as "Samurai Troopers," "New Mobile Report Gundam Wing," "Gasaraki," and "Argento Soma." Characters are designed by Kumiko Takahashi whose previous shows include "Wind Named Amnesia," "Card Captor Sakura," and "Urusei Yatsura: Itsudatte My Darling (theatrical)," among others. Composer Taku Iwasaki is an expert in scoring atmospheric music suited for each show. His previous credits include "Rurouni Kenshin Tsuioku-hen (OVA)," and "Ima, Sokoni Iru Boku." Opening credit theme "Shell'" and ending credit theme "Half Pain" are performed by Bana.