Name: Naoya Kaido
Designation: Snake Orphnoch
Naoya Kaido was an overly eccentric young man inclined to incredibly speedy speeches and constant mood swings. He played the guitar in his younger days, but his teacher's sabotage destroyed some of the motor-skills in his left hand, forcing him to abandon his music. He is later made a 'sired' Orphnoch by Toda/Squid Orphnoch as an example to Kiba and Yuka of how Orphnoch must make allies, using a snap of his finger to trigger Naoya's transformation into Snake Orphnoch. He lost his part-time job because of his newly found enhanced ability and was being targeted by a corrupt employer. Kaido decides to abuse his power for personal gain when he encountered Faiz, with Kiba coming to his aid.

He greatly mistreats Yuka accidentally due to her crush on him. Continuing to struggle with his nature as an Orphnoch, Kaido ends up living with Kiba and Yuka, although he is the least concerned about protecting humans. At times he sides with Smart Brain over Kiba and Yuka, but his powerful and soft-hearted conscience often stops him from committing heinous acts at the last second. He eventually develops a partnership with Keitarou, which results in many harebrained schemes to win the respected woman of their desire, and bonded with Teruo/Arch Orphnoch. He briefly wore one of the six Riotrooper gears under Kiba's term in Smart Brain, the two switched roles, with Kaido throwing away his Riotrooper belt at Kiba in disgust for his friend's new attitude. Though he survived in the TV series, Kaido was eaten alive by the Elasmotherium Orphnoch in the movie shortly after he bares his heart to the dying Yuka

Series:  Kamen Rider 555