Two brothers get toy cars and turn them into an obsession that consumes everything. The racing never stops, the customization never ends, and every competition rewrites what you thought was possible with a machine that fits in your palm. This is pure, unironic passion disguised as a kids' show about Mini 4WD, and it hits because the brothers' hunger to win is the only thing that matters.

Two young brothers, Retsu and Go Seiba, are drawn into the world of Mini 4WD racing after Dr. Tsuchia gives them racing cars of their own. From there, the pair train hard and customize parts for their machines, working toward the Japan Cup, a national competition where racers from all over the country gather to find out who is the very best. Based on the manga by Tetsuhiro Koshita, the sports adventure centers on the two boys and their racing, with every upgrade and training session building toward that big tournament.