Haniwa Phantom Roiza was the Monster of the week on Ep.15 of Kotetsu Jeeg. Roiza was a Dragon type Phantom, with orange wings, with white skull face, Light Green neck, dark torso, and purple color lower body all the way to the tail. Fore Legs were green and gray ending in sharp claws, the hinde legs were Green and dark blue. It's abilities were flight and fire breathing.

Roiza appears right at the start of the episode when Ikima demonstrates the power of the Phantom on a DecoyJeeg. Please with the demonstration, Queen Himika allows the Attack to go through.

Meanwhile, Don and Pancho begin to make tests of their own: making MechaDon fly, which end poorly in crashes, thanks to Pancho's blunders much to the amusement of Hiroshi and the others. Tired of it, Don fires Pancho and leaves. Seen Pancho's leg injured, Michi Uzuki kindly gives her handkerchief to him to ease his pain, much to the delight of the Mechanic. Not long after, Mayumi meets an old man searching all of Japan for Pancho and takes her home where he explains Pancho is the only son of Businessman named Senjiro Hoshikawa and owner of a Zaibatsu, (quote: which is a large industrial group at the hands of a family). While many have a hard time believing this, though the man explains that Pancho's features resemble his father. Don is inform of the matter, while Hiroshi gets a call from the Director, who detects an approaching UFO (Roiza) and Michi and Hiroshi leave to meet it.

Roiza attacks the city, but turns its sights on Pancho, trying to burn him. Michi attacks with the Shooter saving him. Hiroshi arrives and transforms, assembling Jeeg. Despite using its arsenal, the Phantom's speed and flight capabilities help him avoid the attacks. Michi fires the Mach Drills, to give him flight, but the Phantom pops from behind him. Michi fires Shooter Missiles, blasting one of the wings, but it's flying debris breaks into the cockpit, she loses control and crashes, hurting her head severely. Jeeg transforms back and Hiroshi brings an unconscious Michi, allowing the beast to escape. He takes her to the Build Base's medical bay to have her treated. While her condition is not serious, she need to rest for a week, leaving the team without a pilot. Pancho visits to see how she is doing, Hiroshi informs him Don was looking for him.

Pancho later arrives at Don's where he is inform of his Pancho-Sama status, and he takes advantage of it, making Don his subordinate (much to his pain). Through the day and Night, the two begin work on MechaDon's flight mode. Not long after, Roiza, now repair, returns and attacks the Build Base. As the base defends itself and Hiroshi tries to keep Michi resting, MechaDon arrives in it's new flight mode, with Pancho mounting a turret and fights the beast, though the cannon balls prove of no effect. As they become a distraction, Michi begs to be taken to the Big Shooter, which Hiroshi concedes and the two take off.

As soon they arrive, Hiroshi passes the controls to Michi and ejects to transform, but Michi loses control, heading towards the ground. As Don jumps off, Pancho takes control of the MechaDon and saves the Shooter and Michi from crashing, carrying it to the air to fire the Jeeg Components (This would be the only act of genuine heroics shown by the MechaDon1 before its destruction). Jeeg is assembled and takes the chance to fire the Magnetic Ropes, lassoing the Phantom, and dispatches it with Spin Storm. A furious Himika watches, reprimanding Ikima for the latest failure.

In the end, Pancho's parental relation was proven to be a mistake, much to the disappointment of Don, but Michi still gives gratitude for saving her, making him blush.