Koro Sol is magically inadequate, but his parents were a support for him, until they disappeared four years ago. Now 12 years old, he finally has permission to ask his clan leader, but he is expelled from the clan on that faithful day. With his parents declared traitors and their whereabouts unknown, Koro himself who is clueless about what will happen to him. He will follow paths filled with cruelty and danger until he himself becomes the Forbidden Sorcerer.