One winter day, some humans suddenly turned into monsters that massacred those around them. With glowing wings and halos on their head, they looked like angels rather than monsters. The sight of angels slaughtering humans is surely a sign of the impending end of the world. No one knows what their purpose is, and a school was built to train students to be mahou senshi fighting against these angels – ‘the four halos’. Ren looks like a normal student, but he actually has a magic bloodline and was scouted to be a teacher at this school.