In the distant year 3333, three decades after a catastrophic disruption sent a powerful weapon crashing onto the ravaged planet Xevious, a player from the real world of 2025 is abruptly pulled through into the game's universe. He awakens as a strange, helpless figure in the ruins of a prison, without arms or a mouth, utterly lost in an alien and hostile land. There he is found by a robotic companion named PUCK, who declares him her eighth summoning attempt, and a mysterious being grants him a prosthetic arm so he may wield a sword, transforming him into a Swordsman. Together, the two set out across the devastated world, soon uncovering that Xevious lies under the control of a malevolent supercomputer called Gamp, which has corrupted the planet's life and technology alike.