The story takes place in a time when the world is in the pits of despair after being ravaged by a poison called "shinobi" that came to earth via an asteroid. The people run away to the place called "Kairiku," a place that used to be the bottom of the ocean. Here, the people try and protect themselves against the effects of the poison. In such a world, there was a single light of hope. The "Holy Weapon Giga Road" and...