The genius behind the G3 System. Her position within the G3 unit is the system's monitor engineer, which monitors the condition of the operator and the G3 suit during combat from the G-Trailer mobile command base. She was in constant rivalry with Toru Hojo. She is very glad when learning that Shoichi is Agito. In the series epilogue, she left the police force after the Overlord incident and moved to England to work at a university.
A leopard Unknown and the first of the Unknowns, possessing a red scarf around his neck. He targeted the entire Saeki family, killing them one by one. Makoto Hikawa encountered the monster after he killed the wife, sparing him as he was not his target. Hikawa took instand pursuit in G3 gear, overpowered by Luteus until Agito arrived and destroyed the monster with his Ground Form's Rider Kick EPISODE 1
The Alter Ring is a mysterious belt bestowed upon Shouichi by the Over Lord of Light. It holds the "Seed of Agito" and is the source of his power. An enhanced version of the Alter Ring can be seen in his Burning and Shining Forms. As he grows in strength, he would unlock its full powers.