yushakara wa nigerarenai

Once upon a time, big burning rocks were dropped all over the world by the Devil. The soldiers tried to kill the Devil, but they failed.... Many years later, a tradition was found. It was called the tradition of Roto and it included the day of the Devil's revival and the way of sealing him up. The soldiers, who heard the Devil would come back to life again, now set off for adventure to save the world....