One day, Norman is told by his father, "I've given up on you," and is kicked out of his house. This is because Norman couldn't use magic. However, his fate changes after encountering the grimoire, "Geotia." It's a book for commanding 72 demons. Summoned by the book, the demons reveal a shocking truth: Norman has an aptitude for summoning demons instead of magic. He then summons and commands demons one after another. When he has many demons, he becomes the strongest.