[Machine Translation] I will make you apostles of the extinction of mankind! Dark mage Cthu falls into darkness for a certain reason and takes a teaching position at a school for demons in order to destroy the human race. However, the class he is in charge of is full of kind-hearted low class demons who yearn for human culture. Coutu tries to correct them with his wild lessons and sad stories of his own experiences, but in the end, his students' talents begin to grow! Meanwhile, the spirit mage Gardina invades the school with an army. Her goal is to purge Coutu, who betrayed the heroic PT. This is the record of a legendary teacher who was praised in later generations as "the one who controls the darkness.