Yuta Okkotsu is haunted by the ghost of his childhood friend who died in an accident. However, she is not the sweet girl she was in life, but a monstrous and aggressive creature that the boy cannot control. Therefore, the master Satoru Gojo, who had detained him, convinces the youth to enroll in a magic school so that he can learn to control Rika and help people. However, soon Yuta learns that evil spirits are not the most dangerous thing in the world.