Bored, resigned, and unfulfilled, a young man with neither name nor past survives by fighting in underground matches of a sport called Megalobox, a form of boxing that utilizes powered exoskeletons. Calling himself JNK. DOG, he feels trapped in a world of crime, poverty, and ecological collapse. All that changes when he has a chance encounter with Yuri, the reigning king of Megalobox. Now, obsessed with proving himself, JNK. DOG becomes a man driven to do whatever it takes to fight his way to the top of the rankings and take on the champion.