Kyosuke Kiriya

Kyosuke Kiriya (桐矢 京介 Kiriya Kyōsuke) also briefly transformed into what was called Transformed Kyosuke (京介変身体 Kyōsuke Henshintai) by the Hibiki production crew. In the stage shows, this form is dubbed Kamen Rider Kyoki (仮面ライダー強鬼 Kamen Raidā Kyōki) which means "Strong Demon".

Kyosuke Kiriya
Kyosuke Kiriya (portrayed by Yuichi Nakamura, who would later portray Yuto Sakurai (Kamen Rider Zeronos) in Kamen Rider Den-O) is a young man attending the same school as Asumu Adachi and Akira Amami. He appears in the second half of the series wanting to be an Oni. Kyousuke is very strict and competitive, often correcting others of small mistakes (e.g. Asumu's notes) and getting himself and others in competitions that they don't want to do.

His reason for wanting to become an Oni was because of his estranged father. Only seeing what his father did in life, Kyousuke saw becoming an Oni as his chance to be greater than his father. Kyousuke pursued Hibiki as a chance to become his student. But Hibiki saw Kyousuke's reason as selfish and refused to let him become his student. But Kyousuke was adamant about becoming his student. Later he forms a partnership with Asumu and pledged Hibiki to become his students.

After Akira persuades Hibiki to let Asumu and Kyousuke become his students he takes them under his wing. However, Kyousuke struggled in nearly every training session, unlike Asumu. During the Orochi Sealing Kyousuke uses a Henshin Onsa to assume Oni form. After the great battle he leaves no longer needing Hibiki, now that he is a full fledged Oni.