The Makai fight a secret war against the demon forces known as Horrors, evil creatures that manifest themselves through darkness to devour Humanity. On the frontlines are the Makai Knights, given the task of watching over a district and eliminating any Horrors that manifest there. GARO follows the tales of the Knights bearing the title of ‘Golden Knight Garo’, and their duty to vanquish the Horrors and protect Humanity from the darkness.

When the evil Orteca convinces an office worker to contract with and unleash the Spider Deadman, Ikki Igarashi transforms into Kamen Rider Revi to stop them! At his side is Kamen Rider Vice... a devil that lives inside his mind that Ikki has made a deal with!

YouTuber Tomoki Uchikawa, along with his friends Hinako, Souta, and Nanae, head to the former Ishio Village, where there are rumors of people being spirited away, to film a video investigating urban legends. However, their whereabouts remain unknown, and the police discover the rental car they had rented near a tunnel on the outskirts of the village. The video cameras left behind there show shocking images of locked houses, children in armed uniforms, imprisoned adults, and adults being infected by a strange disease, a rotten demon, that occurs on the night of a new moon.