Seiya Kuroki (黒木 誠也 Kuroki Seiya): A criminal on the wanted list who aid Negataros in return for world domination. In the end, he is arrested by Kazuya after a fist fight. Kamen Rider Den-O & Kiva: Climax Deka Seiya Kuroki was portrayed by Kenji Takechi (武智 健二 Takechi Kenji).