In the run-down slums of a futuristic city, the boxer only known as Junk Dog is making a living throwing fights for the mob in underground arenas. That all changes when he has a chance encounter with the champion, Yuri.

Yuri has sought Junk Dog out to test his mettle in the ring, and their encounter will leave the underground fighter a changed man.

There's one month until Megalonia begins, and it looks like Shirato Yukiko's brother, Mikio, is a lock for the final entrant into the tournament. Will Joe and Team Nowhere find a way to secure their spot in the Megalo Box championship tournament?

It's man vs machine, as "Gearless" Joe squares off against Shirato Mikio, who is guided by Ace, an artificial intelligence of his own design.

Joe has risen to the top and finally gets his chance of a rematch with Yuri. Yuri himself also feels joy in his chance to fight with Joe. The final battle begins!