All the incidents occuring around the Girls Remix up to this point were part of Sumire Kurono's plan to create the ultimate Kamen Rider. Now that plan is moving into its final phase. Sumire kidnapes Nayuta Mikazuki again. After performing her final surgery, "Kamen Rider Eins" is finally born. Will the Girls Remix be able to get Nayuta back? And what will become of Nayuta, who has become Kamen Rider Eins?

Smart Brain, once Japan's largest company, lost its power due to repeated internal conflicts and was placed under government control with the goal of exterminating Orphnochs. Mari Sonoda, who is living with Orphnochs at the Western Laundry Store Kikuchi, when Takumi Inui, who had disappeared several years earlier, reappeared.

After his devastatingly fast, samurai-style combat approach sets filmmakers against him, a legendary action star films his own movie—on turf claimed by feuding yakuza gangs, including Japan’s deadliest martial arts assassin.

Takumi, Mari, Masato, and many other people who work at Kikuchi Cleaning Shop are leading their daily lives as usual. One day, a customer visiting the store is suddenly killed by someone, they need to try to find out who the murderer is...