Enigma (謎痕, Eniguma, lit. "enigma mark") was currently under strict regulations by the country. By holding a <Contract Ritual>, it will become a Stigma and gives the host the power of Summoning Magic.Thus, the people, who got an Enigma, all had the obligations to enter the Magic Division to study.This was in order for the precious Enigmas to not be wasted and become combat strength.And it was also in order for Summoning Magic, this dangerous power to be completely placed under the control of the country and the academy. Human's hand harbors an Enigma, which could be called as an Invitation sent by a Diva.
Not all people to wants to become a Stigma Magic User. However, if they are given an a Enigma, it is equivalent of losing the freedom for the future.”