シャドームーン
is a butler who takes care of Sayo and convinces her to become Bishium as part of his plan take over Dai-Shocker. Through his King Stone, embedded with the Stone of the Moon, Nobuhiko can transform into . Once he ousts the former leader of Dai-Shocker, Tsukasa Kadoya, Nobuhiko becomes its leader as he leads the group to hunt down every Kamen Rider. In the end, though he overpowers Decade and Kuuga, Shadow Moon is defeated by Double and destroyed by the All Rider Kick. While shares the same name with Nobuhiko Akizuki, the original Shadow Moon from "Kamen Rider Black", his surname "Tsukikage" means "Moon Shadow".