A mysterious woman claiming to be a witch steals a valuable bag from a man and claims that he can’t satisfy her before vanishing into thin air. Having run across her himself, Shotaro, along with his trusted partner Philip take the case, but quickly find that things aren’t right in Fuuto, starting a new battle for the two-in-one detective Kamen Rider W.
The series is a direct sequel of the tokusatsu series Kamen Rider W. In terms of continuity, considering the whole plot of the series and its tie-in movies and specials it was set after the events of the two Kamen Rider W Returns Specials.