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 actually a very powerful O.P.T, and inside him sleeps a demon of incredible ferocity. He meets up with a girl named Ruby who wants to become a treasure hunter like her famous father before her. Though Jio doesn't believe in friendship, he agrees to be Ruby's bodyguard, and together they go on a dangerous quest to discover as many O-Parts as they can.

Yuria's battle with Python Jack continues, and Python Jack seems to have the upper hand. But Yuria has a trick up her sleeve. Unfortunately, she may need to give up her soul to use it... Meanwhile, Jio bumps into a childhood friend - and some unpleasant memories - he thought he'd never see again. Have the demons of the past been laid to rest, or is there still bad blood between the two?

As the battle between Shuri and Jin intensifies, Anna and Kite remain imprisoned. Meanwhile, Jio and Ball prepare for their battle. Jio is an amazing O.P.T., and Ball is stronger than anyone expected... but their opponent is fierce. Will Jio have to rely on the dark power inside him in order to win?

Our heroes head off to save Ruby but are thwarted by two monstrous guards! Will Ball be able to hold them off while Jio charges to Ruby's rescue? Or will Jio fail his toughest test yet when he's forced to face his own true nature?

As the Olympia tournament continues, Jio squares off against Ikaros to save Ruby. It seems like a fair fight, but Ikaros is not what he seems. Will Jio be able to handle his true form? Meanwhile, the Zenom Syndicate moves closer to completing the Reverse Kabbalah... and Cross arrives at Olympia to take his final revenge against Satan.

Although Ruby has succeeded in saving Jio's mind from the depths of Satan, her soul remains inside Satan/Jio's body. Realizing that Jio has come back, Cross decides not to kill him. But amid the turmoil, Ruby's pendant falls into Jio's hands... and Ruby's body (without her soul) falls into the Stea Government's!

The government of Stea is on the hunt for a pair of rogue O-Parts users. Armed with a high-class piece of weaponry, this devious pair of lawbreaking brothers is ready to hit Stea's special squad with everything they have. Will an even more powerful O.P.T. be able to quell their uprising?

Jio and his new friend Ball, a member of the resistance group fighting against the corrupt Governor Jaga, are in deep trouble. They've successfully broken into Jaga's lair, but are they strong enough to survive a battle with the notorious criminal Wise Yury? Later, Ruby learns more about her father and the secret origin of the pendant he gave her before his disappearance. Could Ruby's simple trinket be one of the most powerful O-Parts of all?!

His prized O-Part Zero-shiki now busted in two, Jio and Ball strike out to locate the only man who can help them: the mysterious and reclusive O-Parts appraiser Kirin. But when they arrive at Kirin's abode, a cotton candy-like canine greets them instead. Is Kirin, a being so feared for his strength that even the Stea government won't bother him, in fact just a puffy pooch? And will Jio and Ruby ever be reunited?

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?

To defeat the legendary O-Part Mexis, Jio was forced to make a dangerous pact with the evil spirit that dwells deep within his heart. Now that the time has come to resume his battle with the man responsible for shattering his old O-Part - Wise Yury, the Crimson Magician - will Jio's newfound strength aid him in stopping this powerful O.P.T., or will his eternal soul be lost in the process?