Kenichi Hibiki, a skilled racing driver and innovative motor engineer, pioneered the experimental "X" engine for the Mach 5. During a pre-completion test drive, a catastrophic accident led to his presumed death. His father, Daisuke Hibiki, salvaged the wreckage and rebuilt the car with the "Safety Seven" system to protect future drivers, galvanizing Kenichi’s younger brother, Go Hibiki, to honor his legacy through racing. Secretly surviving the crash, Kenichi adopted the alias of the Masked Racer, a shadowy figure who covertly aided Go during races. Operating incognito, he thwarted rivals and sabotage attempts to shield his brother, often sacrificing his own victories. This dual role as protector and competitor sparked mounting tension as Go grew suspicious of a familial bond between the enigmatic racer and his late brother. The Mach 5’s origins as Kenichi’s creation remained a central narrative thread, its advanced capabilities and safety mechanisms rooted in his engineering. His apparent death and clandestine interventions underscored recurring themes of legacy, sacrifice, and unresolved family ties within the series.