Gemara was a Haniwa Phantom and was the monster of the week on Ep.6 of the Kotetsu Jeeg series. He was a humanoid type Jamatai Haniwa Phantom, brown, light brown and red (though at times this changes from Brown and Dark Yellow in the episode). He was adorn with a row of three curved spikes in the back of the lower legs and a Red color Tail ornament on the top of helmet and held the traditional skull with horns ornament located on its lower abdomen. His weapons of choice was whip like tentacle he had for a right arm, this could operate on its own if rip off, as well Gemara held a Blade attached to a chain, and like many phantoms, could burrow through the ground.

Gemara is first detected by the Build Base radar system as it burrow its way towards the Kanto Regional Grand Prix, in one of the many attempts to kill Hiroshi, Miwa leaves on the Big Shooter to the region just to keep an eye on the situation. As, the race starts, the Phantom attacks and pins Hiroshi with is car, but also hurts a more experience racer (Hoshikawa) who came to help Hiroshi. Hiroshi escapes and transforms into Jeeg and fights the Phantom, in the process rips its whip arm off with a Knuckle Bomber, tossed it with Spinstorm Beam and then grapples him with Magnetic Ropes. Jeeg then tries to crushed it with the Jeeg Breakers, but before it could succeed, the Arm Whip takes life of its own and hits Jeeg in the face, losing his grip allowing Gemara to escape.

After the attack, Hoshikawa is taken to the hospital, where he tells both Hiroshi and Don his reasons why he was racing, to earn the money for his daughter, Chie, who was left paraplegic and bound to a wheelchair after a car accident, something Hoshikawa feels responsible for. Feeling for his friend, Hiroshi takes on the take care of Chie while Hoshikawa recovers, and promising to help his daughter walk again. Meanwhile, in the Jamatai Kingdom, Ikima reports to Queen Himika the results, feeling please they may have dropped Hiroshi's sense of security, she orders Ikima to have Gemara ready for the next assault.

Back at Hiroshi's place, he helps Chie to walk, though the many attempts lead to failure, but Hiroshi been Hiroshi scuffles at any attempt from the others to help out or advise and his attempts to help Chie becomes a distraction from his work at the Build Base, which is in the process of developing the new Bazooka for Jeeg believing the Phantom a weak monster. After various failed attempts, Chie recognizes she won't walk again, and after an argument in where Hiroshi slaps Chie making her leave the house_

...Our Hero, ladies and Gentlemen!...

Chie takes time to think alone, when Gemara come out of the ground. Hiroshi is alerted especially with Chie missing, and Don and Pancho take off on the MechaDon, where they find the Phantom going after Chie who loses her grip and falls from her wheelchair, but Gemara disposes of MechaDon with no effort to it. Hiroshi then arrives and distracts the Monster to go after him, Michi then shows up on the Big Shooter and fires the Build Components to form Jeeg.

The two Giants fight, but Gemara demonstrate its true strength, tossing Jeeg and then grappling him with is Whip Tentacle. It then brings out as chained Moon crescent shape Blade from its right arm, and hits Jeeg with it, doing severe cuts and ripping it right arm. Michi tries to assist, but this doesn't stop the Phantom. She then fires the new Bazooka to Jeeg and uses it on Gemara, disposing of the Monster with one hit.

After a wounded Jeeg falls to the ground, Chie begs him to stand up, and she does so by standing up herself. Seeing this, Jeeg stands up and the two walk to each other. Later, everyone gathers at the hospital with Hoshikawa been release and grateful to see his daughter walking again.