Long ago, there was an ancient story of the Light Harbinger and the Shadow Manipulator felling down an army of 200,000 men. It was a massacre, and an unbelievable feat that historians deemed it a fantasy.
Fast forward to the modern era, superhuman abilities were thought to be nonexistent. Kurayami Hikari was just a normal high school student... until a person came out of his shadow.
Would you like to be my successor?