This world revolves around mob characters. The demon king was also defeated by an accumulation of effort over many generations of mob characters.
The current timeline: Year 865 of the Mob Calendar: The blacksmith forges a strong weapon that can defeat the demon king Year 1322 of the Mob Calendar: A fortune teller gives birth to a child who will defeat the demon king Year 1332 of the Mob Calendar: A nun provides great assistance to the child who will defeat the demon king.