He can fly up to 300km/h, and armed with a bow gun that fires owl-feather darts, Buro assumes the form of a young man wearing sunglasses. When his turn came, he spent the five hours in Tokyo District 23 using his bow gun to snipe down people by the nines from the air, having all 126 victims die of a myocardial infection. Kuuga intercepts Buro at the Hygeia Building in Shinjuku, attempting to fight him in Pegasus Form as he temporary upgrades to Rising Pegasus Form. To evade his demise, Buro rips off his right wing when it was hit by Kuuga's attack and runs off to regenerate it. Once healed, Buro forces Kuuga out for a final battle, bringing out his Rising Pegasus Form. However, it took three hits from Kuuga to kill him.

She can breath underwater up to 100 degrees Celsius(212 degrees Fahrenheit), and armed with a whip, she assumes the form of a young woman in a black cheongsam with black lips and a love for classical music. When her turn came, Bemiu uses Chopin's Revolution to plan out her killing spree, murdering her victims by going to public water areas and using her whip to pierce sixteen of those each in the pool, totaling 58 victims of frostbite-induced cardio paralysis in the four pools she visited. But when the police closed down the public swimming areas after getting her pattern, Bemiu alters her plan to attack the people at a beach until Kuuga intervenes in Dragon Form. Once assuming Rising Dragon Form, Kuuga kills her as he chucks her into the sea.

Armed with a supply of morning stars created from his rings, he assumes the form of a man in Yakuza attire with a gambling streak. Using a roulette table to select the number and color to pick out a random location straight from a tall building he occupies, Gamego tosses his weapon to kill as many people to get his quota of 54 for each location. Kuuga fights him in Rising Titan Form, but was overwhelmed and defeated as the hard-shelled Gamego takes his leave, knocking out Junichi Chono in the process. Using a game of poker and starting anew at West Shinjuku, Kuuga battles Gamego as Ichijo uses the prototype Neurogenesis Bullets to disarm the Grongi as Kuuga uses the Try Gouram to bring their fight to a disclosed area, assuming Rising Mighty Form to kill the Grongi.

The first of the Go to appear when he intervenes in Kuuga's fight with Gooma before leaving the scene and then formally introducing himself when Bemiu starts to play. Assuming the form of a young man wearing a scarf and carries a coin, Badaa rides a bike named the Bagibuson as his weapon that can reach speeds of 400km mph. When his turn came, he begins to kill 99 motorcyclists within a 72 time limit. When the TryChaser 2000 is damaged, Kuuga is left at a disadvantage as Bada leaves with a promise to save him for last in his game. By the time Badaa reached 98, he decides to finish off Kuuga. However, after being barraged with bullets, Badaa is driven into a secluded location where Kuuga meets him on the BeatChaser 2000, outrunning him before he fatally knocked Badaa off his bike.

Armed with needles, Jaraji assumed the form of youth in black who enjoys human suffering and snaps his fingers when able to move at fast speeds. He supported Gamego in his game before his death. When his turn came, Jaraji started to target 90 people by shooting his quills into them, having them die of encephalitis in four days. While going after Kazuya Ikuta, killing the police, Jaraji is interrupted by Kuuga, taking offense to it and leaving Kuuga wounded with a warning to stay out of his game. However, because some of his victims committed suicide, Jaraji is forced to find replacements before the 12th day ends. But when he was about to kill Kazuya to finish the game, Kuuga attacks Jaraji in a berserk rage, assuming Rising Titan Form to brutally kill Jaraji.

Armed with a poison claw, Zazaru posed as a woman with a fan who loves to paint her nails, the medium of her weapon and her game pattern. She supported Gamego and later made an enemy of Gooma after calling him weak. When her turn came, she targeted people in ten of the type of moving object like taxies and elevators that reflect the color pattern of her nails, melting them down with her strong acidic blood. This acid is trouble as it is extremely flammable and cause mass destruction if she is attacked. During her game, she gets ambushed by Gooma and the two fight until Kuuga arrives, allowing her to escape to resume her game in spite of Dorudo's warnings not to underestimate humans like Bemiu had. Kuuga along with the police force charges on Zazaru as he assumes Rising Pegasus Form with his aided Beat Gouram to shoot her down.

Jaaza assumes the form of a glasses-wearing woman in a dark green suit. She hates to fight but she knows she must continue for her own survival and prefers killing those too weak to fight back. She is armed with a harpoon. When her turn begins after modifying herself from her default Quick Form, she goes all out to kill 567 within five hours while leaving internet blogs proclaiming her actions minutes prior. After slaughtering the mostly elderly 243 passengers of Rainbow Airlines in one go while posing a passenger, she kills the pilot after having him relay a message to the police of her intent. Jumping out of the crashing plane and swimming all the way back to Tokyo, she manages to severely wound Kuuga while his guard was down. After meeting with Baruba, she heads off to kill the remaining 327 at Sunflower Cruise, most of which were children. Kuuga arrives on Gouram to stop Jaaza in Dragon Form. However, she evolves into her Herculean Form, armed with a large sword and Kuuga switches to Rising Titan Form, taking their fight into the ocean floor as he kills her.

Baberu assumes the form of a man in his forties with a headband and black lips. When his turn came, he targeted underground centers, using his default Grapple Form's natural strength and armed with a pair of brass knuckles to block all escape routes to ensure the police don't interfere in his game to kill 682 people within four plays. On the third day, Baberu battles Kuuga, defeating his Rising Titan easily in Herculean Form, armed with a war hammer, until Ichijo uses the Muscle-Relaxing Bullet to weaken the Grongi as Kuuga takes him to the location to finish him with his aided Rising Beat Gouram.

Armed with various weapons similar to Kuuga, Gadoru assumes the form of a man in militant garb. As the Go's leader, he intervenes in battles. After undergoing training to ready himself, Gadoru heads to the police department to find worthy opponents to fight as part of his game. When confronted by Kuuga in his default Grapple Form, Gadoru, reveals his new ability to the different powers of Kuuga, Quick Form, Shooting Form, and Herculean Form, before defeating Kuuga at full-power in Shocker Form. But due to Ichijo, Gadoru's game had to bereset as the Grongi attempts to kill Dorudo for failing his part. After Dorudo retreats, Gadoru attempts to kill Ichijo upon being wounded by the officer's Nerve-Breaking Bullets as Yuusuke arrives to battle the Grongi as Kuuga. Once taking their fight to the woods, Kuuga assumes Amazing Mighty Form and destroys Shocker Form Gadoru.
A wild boar Grongi labeled as "Unidentified Life Form #40". Destroyed by Kuuga Mighty Form's Mighty Kick. Only appears in he Super Secret Video.
Other Grongi :: Zu Group | Me Group | Go Group