Kamenrider Kuuga

   Yuusuke Godai/Kamen Rider Kuuga : The young adventurer who changes into Kuuga. He is a happy-go-lucky and honest person that fights to protect everyone's smile. Yuusuke and his sister, Minori, lost their mother while they were both young and their father when they were older. He was born in Hokkaid? Prefecture on March 18, 1975. His blood type is O.

Kaoru Ichijo:
The police inspector who assists Godai in fighting the Grongi. He is a model policeman that firmly believes in doing the right thing. Though he is very strict with himself, he will do everything he can, even bend police rules, to help Yuusuke fight the Grongi. He was born in Nagoya City in Aichi Prefecture on April 18, 1974. His blood type is AB.
Sakurako Sawatari: A friend of Godai who translates the ancient "Lintonese" transcripts that tell of Kuuga and the Grongi. At first she was against helping because she was worried about Yuusuke, but now she believes in him fully and works hard to help Yuusuke understand his powers by deciphering the writings. She was born in Gunma Prefecture on October 30, 1976. Her blood type is B.

Nana Asahina :
Tamasaburo's niece, who helps out at the Pore-Pore Tea.

   The Grongi Tribe is a mysterious ancient civilization that can transformed into their monster forms to kill people for their ruthless game, the first being their rival civilization the Linto. But Kuuga defeats the leader of the Grongi and seals all 2001 of them away. However, by present day, the newly resurrected Deguba revives his tribe from their rest and resume their game on the human race. They are referred by the Police as Unidentified Lifeforms (also known as "Unidentified Creatures" in a newspaper during the beginning of episode 5) Mikakunin Seimeitai. Each of them possess a strange artifact in all of their bodies. Those seen to assume human form are labeled as "B", each the human-like Grongis possessing a tattoo that resemble their true animalistic forms. Unidentified Lifeform #B1 only remains in human form for the rest of the series. The naming pattern of the Grongi are "Creature type".

   N- Daguba-Zeba is the lord of the Grongi Tribe responsible for murdering the archaeologists before resurrecting the Grongis in modern times, labeled "Unidentified Lifeform 0" by the Police. He appears to have killed other Grongi as well, as not all of them appeared in the series due to their unworthiness to be in the game. Once he appears physically, Daguba is labeled as "B13" before being killed by Kuuga Ultimate Form.

Kamenrider Agito

   Agito is the first Kamen Rider series to feature the three main types of Riders: a mystical Rider (one that draws power from ancient technology or mystical methods), an organic Rider (one whose anatomy changes to become a Rider), and a high-technology Rider (one who is either a cyborg or uses advanced technology to fight). A man named Shoichi Tsugami seemingly has no memory. He doesn't know who he is, where he came from, or how he came upon his peculiar circumstances. Tsugami, seemingly for no reason, transforms into a powerful superhuman, Agito, whenever in the presence of the beings referred by the police as the "Unknown", a race of powerful monsters that have been causing murders around Tokyo, targeting certain people as their prey. In response, the police department unleash their newest weapon: the G3 powersuit, originally developed to fight against the "Unidentified Lifeforms", the enemies of Kamen Rider Kuuga. G3 and Agito don't know whether they should join up and defeat the Unknowns, their common enemy, or to combat each other, keeping the mysteries that entwine them separate. Ultimately, even more mysteries unfold, with the appearance of Kamen Rider Gills, who is on a search to uncover why his father committed suicide. These mysteries and others collide, as the true nature of Agito would ultimately determine the fate of humanity.