Fuuto PI (Japanese: 風都探偵, Hepburn: Fūto Tantei) is a Japanese manga series written by Riku Sanjo and illustrated by Masaki Sato. It is a manga sequel to the 2009 tokusatsu live-action series Kamen Rider W, part of the Kamen Rider franchise. The manga was created by Sanjo in response to the immense popularity of Kamen Rider W, serving as a sequel while exploring darker stories. It has been serialized in Shogakukan's seinen manga magazine Big Comic Spirits since August 2017, with its chapters collected in 18 tankōbon volumes as of March 2025. The series follows Shotaro Hidari, a private detective at the Narumi Detective Agency, and his partner, Raito "Philip" Sonozaki. Together, they solve cases and combine their abilities to transform into the superhero Kamen Rider W, defending Fuuto City from threats alongside new allies. Set two years after Kamen Rider W, the manga shifts focus more toward Shotaro rather than Philip. This led to the introduction of Tokime, an amnesiac woman who becomes Shotaro's assistant and is mysteriously connected to the new enemies they face. Since the manga was published in a seinen manga magazine, Sanjo incorporated more mature themes—content that would not have been possible in Kamen Rider W. An anime television series adaptation by Studio Kai, Toei, and Ishimori Entertainment aired from August to October 2022. An anime film, subtitled Kamen Rider Skull no Shōzō, premiered in November 2024. Critics praised the manga for its compelling mix of mystery and dynamic fight sequences. Similarly, the anime adaptation was lauded for effectively introducing the Kamen Rider concept to new audiences, despite being a sequel to the original television series.