FXs, two-legged motorcycles equipped with arms, and racing with these machines have surged in popularity due to the sport's heightened propensity for violence. Makoto drives for a D-ranked FX team that is deep in debt yet possesses a thirst for victory. With the chance to compete in the upcoming prestigious Open Cup, Makoto and his team desire nothing more than to secure the substantial cash prize. The sole obstacle is that their homemade FX lacks the power to win the gold. However, their luck shifts when they encounter Gou—a mysterious man who provides the team with a brand-new, state-of-the-art engine—which they eagerly accept without realizing that it may cost them more than just money.