In a not too distant future, mankind battles over O-Parts, powerful relics from an ancient civilization. Jio is a young boy with a tragic past who only trusts one thing in the world: money. Little does he suspect that he is also a very powerful O-Parts Tactician (O.P.T.), and inside him sleeps a demon of incredible ferocity. With his partner, Ruby, Jio embarks on a dangerous quest to acquire as many O-Parts as he can. Jio's friend Ball always dreamed of being strong--strong enough to help the resistance movement stop the maniacal governor Jaga who has a stranglehold on his hometown, and strong enough to defend his friends and his sister. Now that he too is an O.P.T., it looks like Ball might stand a chance! Can he, a novice when it comes to O-Parts, defeat a powerful member of the Zenom syndicate single-handed ?