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.

Separated into various groups and confronting a variety of threats, Jio and his friends hope they're reaching the end of their struggle to break the Zenom Syndicate. It's been a tough final push, and as they know only too well, no fight is over until it's over!