The age-old battle between good and evil, represented by the opposing forces of angels and demons, remains an ongoing struggle with no resolution in sight. In this particular tale, a demon by the name of Sword is locked in perpetual conflict with Io, his angelic counterpart. After engaging in a grueling 101st battle, both combatants sustain severe injuries and plummet towards Earth. Desperate to survive, Sword locates a suitable vessel to inhabit - a weak and hapless boy who was in no condition to offer any resistance.
As he settles into his new form, it becomes clear to Sword that the body he has chosen is far from ideal; his host is a stereotypical "nerd" with little to no physical prowess. Adding insult to injury, Io has also managed to take possession of a body, but it happens to belong to the twin brother of Sword's host - a violent and unstable individual whose behavior is the complete opposite of Sword's own. Making matters worse, neither Sword nor Io can wield their full power in these imperfect hosts.
As the situation grows increasingly chaotic, Sword realizes that he is now being hunted by both his demonic and angelic adversaries. Will he manage to survive this predicament, or will his luck finally run out?
