Zu Group

The Zu Group contains lower tier Gurongi. The creatures of Zu group which is not in the list are considered to have been murdered by Daguva, without acquiring the right of the game. The one that are qualified are brought into the game by writing their names on a portable black board and using the beads of their bracelets to mark the number of people they have killed. Their leader is Zu-Zain-Da.

Zu-Gumun-Ba
Zu-Gumun-Ba (ズ･グムン･バ)
 * Statistics:
 * Code name: "Unidentified Life Form #1" (未確認生命体１号)
 * Tattoo: Spider
 * Voice: Tetsuo Sakaguchi (坂口 哲夫)
 * Episodes: 1-2
 * Destroyed by: Kuuga Mighty Form's Mighty Kick

The first of the Gurongi to appear, Gumun first appeared in south Nagano weaving a web on the 1532 MK Building, overwhelming law enforcement as he attacks them without mercy with his power to spray webbing and create claw extensions on his hands. Crashing into the police station, Gumun slaughters the police officers until Yuusuke puts on the Arcle, being targeted by the Gurongi as he becomes Kuuga in "Growing Form" in a fight that ends with Gumun being knocked out of a helicopter several feet in the air. Surviving the fatal fall, Gumun reappeared to settle the score while aiding Gooma. But in the end, Zu was mortally wounded by Kuuga' Mighty Kick, screaming his intent to kill Kuuga as he explodes.

Zu-Gooma-Gu
Zu-Gooma-Gu (ズ･ゴオマ･グ)
 * Statistics:
 * Code name: "Unidentified Life Form #3" (未確認生命体第３号) and "B2" (Ｂ群２号)
 * Tattoo: Vampire bat
 * Actor: Mitsuru Fujio (藤生 みつる). Fujio later appears in the New Year Special as one of five customers at the Pore-Pore Tea Cafe with similar mannerisms to their Gurongi lookalikes. Yuusuke notes his familiarity with the Gooma lookalike in particular.
 * Episodes: 2-39

Among the first Gurongi in Nagano, the photophobic Gooma commits vampirism on five humans in a single night until sunrise where he murders the preacher Father Jose and dons his attire to use the Church as a base of operations. He managed to overpower Kuuga until being driven away by the headlights of a police car. When Ichijo uncovered the truth, he battles Gooma as the church is set on fire and Yuusuke assumes Mighty Form for the first time. However, though he had the advantage with Gumun's aid, Gooma retreats when dawn occurs. Later donning a black trench coat and fedora to protect himself from direct sunlight, Gooma was temporary removed from the game as a result and becomes Ra-Baruba-De's underling when the Zu lose the right to play. His flying from Tokyo to the site of Gurongi burial grounds in Nagano, finding a discarded piece of Daguva's body item and having it refined before using it on himself to evolve to a state where he can now resist sunlight and assume a dark-skinned and brown,long haired Strengthened Form (強化体). But the evolution increased Gooma blood-lust as he actually attacks Baruba to force Daguva's location out of her with the intent to kill Daguva and get all his power. But when Gadoru overwhelms him to cover Baruba's escape, Gooma is forced to retreat as the final stages of his evolution take effect, his hair grayed in the process with the ability to assume a white-haired and armored Ultimate Form (究極体). Going on a killing spree in Chiba, killing as many people as he could before Daguva comes for him. But Kuuga arrives to fight him in Titan Form as Ichijo uses a device specially made to disrupt Gooma's via sound waves. But Gooma manages to destroys the device and was about to kill Kuuga when Daguva finally arrives. He runs off to fight Daguva, only to be slaughtered by him with his corpse found by Yuusuke and Ichijo as it is taken for medical analysis, leading to the development of the Nerve-Breaking Bullets. Gooma's name in Japanese comes from the readings for "fiend" (強魔).

Zu-Mebio-Da

 * Zu-Mebio-Da (ズ･メビオ･ダ)
 * Statistics:
 * Code name: "Unidentified Life Form #5" (未確認生命体第５号)
 * Tattoo: Leopard
 * Actor: Chikako Shiratori (白鳥 智香子)
 * Voice: Kumiko Saijo (西條 久美子)
 * Episodes: 3-4
 * Destroyed by: Kuuga Mighty Form's Mighty Kick

Mebio,assumes the form of a woman dressed in black,was one of the first Gurongi that appeared in Tokyo. She was able to run up to 270 km/h, she fought Kuuga and ended up losing her eye to gunshots by the police, killing Enokida's husband in the process. She was eventually destroyed by Kuuga after recovering from her wound.

Zu-Baduu-Ba

 * Zu-Baduu-Ba (ズ･バヅー･バ)
 * Statistics:
 * Code name: "Unidentified Life Form #6" (未確認生命体第６号) and "B5" (Ｂ群５号)
 * Tattoo: Grasshopper
 * Actor: Nobuyuki Ogawa (小川 信行)
 * Episodes: 3-6
 * Destroyed by: Kuuga Dragon Form's Splash Dragon

The arrogant Baduu assumes the form of a young man with a scarf. When he begins his part in the game in Suginami, Baduu grabs unsuspecting people where the smoke from a factory doesn't point, leaping high enough so his victims can fall to their death. Kuuga arrives before Baduu kills a police officer, with Baduu overpowering Kuuga's Mighty Form with his jumping abilities, though he retreats when the smoke comes their way. Baduu later resumes the game, almost killing Ichijo and attacking the Police before Yuusuke arrives to finish the fight. Though losing at first, Kuuga manages to master Dragon Form's power thanks to Sakurako and kills Baduu.

Zu-Zain-Da

 * Zu-Zain-Da (ズ･ザイン･ダ)
 * Statistics:
 * Code name: "Unidentified Life Form #22" (未確認生命体二十二号) and "B3" (Ｂ群３号)
 * Tattoo: Rhinoceros
 * Episodes: 3-12
 * Actor: Akira Nogami (野上 彰). Nogami later appears in the New Year Special as one of five customers at the Pore-Pore Tea Cafe with similar mannerisms to their Gurongi lookalikes.
 * Destroyed by: Kuuga Mighty Form's Mighty Kick

The leader of the Zu, Zain is able to assume the form of a hulking strongman with a temper. Soon after the Me group's turn begins with the Zu no longer worthy to play, and when their first hideout got compromised by the police's smoke bombs, Zain starts acting on his own by attacking trucks and jabbing the drivers to death with his horn. He overpowered Kuuga in both human and Gurongi forms when Biran intervened as Zain stole his turn. While Zain resumes his attack on large motor vehicles, Yuusuke manages to perfect his Mighty Kick to finally kill the Gurongi.

Other Zu Gurongi

 * Zu-Gujiru-Gi (ズ･グジル･ギ): A whale Gurongi labeled "Unidentified Life Form #7" (未確認生命体第７号). Destroyed by Kuuga Mighty Form's Mighty Kick.
 * Zu-Garuga-Da (ズ･ガルガ･ダ): A kangaroo Gurongi abeled "Unidentified Life Form #8" (未確認生命体第８号). Destroyed by Kuuga Mighty Form's Mighty Kick.
 * Zu-Miuji-Gi (ズ･ミウジ･ギ): A Sea slug Gurongi labeled "Unidentified Life Form #9" (未確認生命体第９号). Destroyed by Kuuga Mighty Form's Mighty Kick.
 * Zu-Gazubo-De (ズ･ガズボ･デ): A Nepenthes Gurongi labeled "Unidentified Life Form #10" (未確認生命体第１０号). Destroyed by Kuuga Mighty Form's Mighty Kick.
 * Zu-Daago-Gi (ズ･ダーゴ･ギ): An octopus Gurongi labeled "Unidentified Life Form #11" (未確認生命体第１１号). Destroyed by Kuuga Mighty Form's Mighty Kick.
 * Zu-Nezuma-Da (ズ･ネズマ･ダ) and Zu-Nezumo-Da (ズ･ネズモ･ダ): Rat Gurongi labeled "Unidentified Life Form #12A" (未確認生命体第１２号Ａ) and "#12B" (第１２号Ｂ). Nezuma died a mysterious death in an explosion by a police force's gunfire and Nezumo was destroyed by Kuuga Mighty Form's Mighty Kick.
 * Zu-Jamoru-Re (ズ･ジャモル･レ): A gecko Gurongi labeled "Unidentified Life Form #13" (未確認生命体第１３号). Destroyed by Kuuga Mighty Form's Mighty Kick.