Hameln no Violin Hiki

Pandora's Box led a cursed existence. Through the curiosity of a woman, evil was unleashed and very nearly covered the world in darkness. Miraculously, humanity managed to seal Maou Kestra back into the box, but only with immense sacrifices. Even without their lord, the demons are still a formidable force that has only grown stronger with time, locked in the abandoned capital of the North, Hameln. Fifteen years have passed since that fateful battle...