This series premiered in late 2009 following the finale of Decade. Shotaro Hidari is a private investigator in the ecologically-minded city of Futo who works with his partner Philip to investigate crimes that involve users of Gaia Memories which transform them into monstrous beings known as Dopants. Shotaro and Philip have their own set of Gaia Memories that they use in conjunction with the Double Driver belt, with Philip's mind travelling into Shotaro's body to fight as Kamen Rider Double. With their landlord (and daughter of their mentor) Akiko Narumi, Shotaro and Philip protect Futo all while discovering more about the past that Philip cannot remember.