In the year 2150, humanity stands on the brink of extinction. A powerful faction of robots known as The Last Race has annihilated the governments of Earth and imposed its dominion over the planet. Driven to the edge of survival, humanity is forced to flee to Mars—where they discover a mysterious gemstone. When fused together, these stones can forge a weapon of immense power. That weapon is called the Fire Sword. Those who are able to wield it are known as Swordsmen.