Kunado Chronicles

One day, metals have gained a will and randomly began to attack humanity all over the world―――

Without knowing the cause, all the civilization and history on the earth were destroyed, and mankind has been hit by unprecedented catastrophes for about 1,000 years.

Humans drastically reduced their numbers and managed to survive while resisting the attack against the metal with will Tekki.

Many of the remaining humans have awakened to their supernatural powers, and devoted themselves to the days of battle. Meanwhile, a girl named Natsuhime, one of the warriors belonging to the frontier country of Kanto, defeats Kurokami, the greatest threat of Tekki.

The people of Kanto who survived are shaken and rejoices the disappearance of a thousand-year-old threat to human existence.

This story revolves around the boy Shin, who has no memory of being found in the remains of Kurokami after the battle. It is a story of mankind's revival and how it reconstructs history from the former civilization that humans lost to Kurokami.

Introduction translated from  DMM official summary