The battle involving the whole Clover Kingdom is finally over. But because of the battle, the kingdom was heavily damaged, so the Magic Knights were busy trying to repair everything. Meanwhile, someone rather unexpected shows up in front of Asta and the others and states three problems that will come up for the Clover Kingdom. Asta and the others are surprised, but just as they were told, someone showed up to try to judge Asta and his devil power.

Because she used forbidden magic, Nero survived for centuries. In the back of her mind, memories from long ago start to replay in her head. From when Nero was still called Secré and when Secré first met the most powerful and talented mage in the Clover Kingdom, Prince Lumiere. They become friends with Licht and the other elves, but due to the evil plans of a devil, the humans end up killing all of Licht's comrades. Because of that, Licht ends up turning into a demon and Lumiere finds him in that state. What will he have to do to protect the ones he loves?