Redline, Megalo Box Recommendations
A virtually identical premise (a contestant that wants to leave the world of rigged-up matches in order to pursue his search for glory) is the first thing that links these two impressive works, alongside an extremely likable character, a futuristic setting and their shared dream to win the biggest, most important tournament they'll ever join.
Both are love letters to both the sports genre and the coming-of-age subgenre, where your favorite lowest common denominator (JP in Redline, JD in Megalo Box) fights against the odds and many opponents in order to become someone and accomplish his dreams.
TL;DR: Megalobox and Redline share loosely similar premises, characters and settings, so if you like one, the other should satisfy you as well.
JP and JD are both underdogs and outcasts in their respective futuristic sports (racing and boxing), participating in fixed races or matches for money. But they both aspire to prove themselves in their sports by making it into high-stakes competitions (the Redline race and Megalonia tournament, respectively).