Speed Racer is an eighteen year old race car driver, and is one of the youngest in the international racing circuit. Speed is motivated by the disappearance of his older brother to become the greatest driver in the world. Driving the car his father built for him, the Mach 5, He just may have what it takes to become the best. In addition to his masterful driving skills, Speed is a martial artist with a strong sense of justice and frequently finds himself battling terrorists, corrupt racers and criminals who want to win the races and hurt innocent people for their own crooked and twisted reasons.
In the original Japanese version Speed's name is Gô Mifune. HIs father who built the Mach-gō (The Mach 5) is named Daisuke Mifune. His Race Car company is named after the family name Mifune. So when Gô sports a white open-face helmet has an M on it (representing Mifune Motors), as does the car Mach-gō. When not racing he wears a blue shirt with a yellow "G" for his first name Gô. Trixie's name is Michi Shimura therefor the "M" adorning her blouse stands for Michi.