Philip, originally named Raito Sonozaki, emerges as a pivotal force tied to the Gaia Memories and the Sonozaki family’s underworld. Created through clandestine experiments, he was imprisoned within the True Gaia Memory beneath the family mansion as a child, transforming him into a data-driven entity with the unique ability to synthesize new Gaia Memories. This ordeal granted him access to the Gaia Library—a mental repository of all documented human knowledge—which he strategically harnesses to dissect mysteries by linking case fragments.

Rescued during "Begins Night" by detective Sokichi Narumi, whose self-sacrifice secured his freedom, Philip forged a partnership with Sokichi’s apprentice, Shotaro Hidari. Together, they merge via the Double Driver to become Kamen Rider W, battling Dopants warped by tainted Gaia Memories. His physical form dissolved during the Sonozaki family’s catastrophic Gaia Impact scheme, but he reemerged reconstructed through Earth’s data streams, sustaining his alliance with Shotaro.

In cross-media conflicts such as *Movie War Mega Max*, Philip confronts threats like Foundation X’s exploitation of Gaia Memory tech. The *Fuuto PI* storyline delves into his shifting rapport with Shotaro as they tackle illicit Gaia Memory trafficking. His expertise in deciphering fractured Memories—exemplified by analyzing Tokime’s emotion-charged Joker Memory, which echoes Shotaro’s—proves vital in exposing dangers like Yukiji Bando’s High Dope project.

Philip’s journey grapples with transcending his origins as the Sonozakis’ instrument to carve an identity as Fuuto’s guardian. His methodical intellect offsets Shotaro’s gut-driven resolve, forging a symbiotic duality. Though *Fuuto PI* spotlights Shotaro’s evolution, Philip remains integral in orchestrating countermeasures against enemies and guiding allies such as Tokime, aiding her probe into Shadow Fuuto and her own obscured past.