Takumi Tateishi is the lead mechanic at Hibiki Motors, maintaining and upgrading the Mach 5 race car piloted by Go Hibiki. He engineered the "Safety Seven" system, a collection of sophisticated technological replacements for the original vehicle's capabilities. This suite features the Aero Jack for aerial jumps via wing deployment, Balloon Tires that expand for rugged terrain, Cutter Blades as laser-based cutting tools, a Defense Shield forming a protective cockpit canopy, an Emergency Wire twin-hook winch for maneuvering, Fish Diver for submersible operations, and the Gallant reconnaissance and combat drone. His technical proficiency underpins Go Hibiki's racing efforts in the World Earth Grand Prix Association. Takumi debuts in Episode 20, facilitating the adoption of Rocky, a primate companion bonded to Wataru Kazami. His contributions are essential to the Mach 5's functionality during competitive races and external crises.