Ruby's dream: to become a famous treasure hunter. Jio's dream: to rule the world! 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. Swallowed by Nehema, the largest of all Demon Recipes, Jio and his friends make their perilous way through the various ruins and monuments they find inside. Meanwhile, Kirin comes face to face with his nemesis, his twin brother Kujaku, and the reason for the enmity between these siblings is revealed!