In the wind-powered Fuuto City, private detective Shotaro Hidari runs the Narumi Detective Agency with his partner Philip, the only person who can search the all-knowing Gaia Library. Together they transform into Kamen Rider W to stop Dopants, criminals who gain monstrous powers from devices called Gaia Memories. When a mysterious woman named Tokime surfaces at the center of a run of thefts and killings, the pair takes the case and starts digging into the past she cannot remember. This continues the Kamen Rider W tokusatsu series.