Yoshio Kobayashi is the human form of the Rabbit Orphnoch and a minor antagonist in Kamen Rider 555.
A young man who just became an Orphnoch. He attempted to commit suicide but was saved by Naoya Kaido who brought him under his wing. The two managed to trick the Faiz and Kaixa belts away from Takumi and Kusaka. However, Murakami told the pair that only one of them could join Lucky Clover, offering the position to the one who kills Yuji Kiba. By then, Yoshio took Kaido's words to heart and got dirty by abducting Yuka Osada, which vexed Kaido. Though he escaped retribution from the renegade Orphnoch, Yoshio was killed by Kaixa's Gold Smash.
- Yoshio Kobayashi's actor, Masato Uchiyama, would later go on to play Shun Kageyama 3 years later in Kamen Rider Kabuto.