Set in the New York City of the late 1980s, the story follows a chance encounter that forges an unlikely partnership between two men bound by desperation and an unyielding dream. On the streets of Brooklyn, a gangleader and former boxer named Alex Gordon, who suffers from a malignant tumor and has been given only a year to live, witnesses a brutal street fight. The victor is a 19-year-old Japanese-American named Guy Hyuuga, a natural brawler with overwhelming power and a fierce survival instinct. Gordon, once a legendary trainer haunted by the memory of a pupil he watched get shot to death in the ring, instantly recognizes Guy's potential as the vehicle for his lifelong ambition: to produce the world heavyweight champion.

Guy initially has no interest in the sport, but his life is upended when a local gang shoots his father, Ryu Hyuuga, in a dispute over a protection shakedown. To cover the massive medical bills for his comatose father, Guy reluctantly agrees to join Gordon and trains under their mutual acquaintance, a former light-heavyweight contender named Lucky Roman. Roman himself is a gay man quietly dying of AIDS, and he takes on the role of Guy's trainer out of a rediscovered sense of purpose. Breaking into the professional world as a heavyweight, Guy discovers that his raw street-fighting instincts can be refined into a devastating signature blow: the Tornado Upper, a punch with enough explosive force to lift opponents off the canvas.

Guy tears through the early ranks of the division, winning eleven consecutive fights by knockout, before reaching a critical obstacle: Hilton Hammond. Hilton is Guy's childhood friend, a handsome and coldly tactical Olympic gold medalist who was adopted out of the same traveling circus where the two boys once performed together. Their climactic fight for the right to challenge the unified heavyweight champion, Iron Texon, ends with Guy suffering his first and only loss, and Hilton suffering permanent brain damage. Due to Hilton's broken condition, the boxing authorities grant Guy the shot at the title anyway. The final narrative arc revolves around Guy's journey to prepare for the unbeatable Texon, a near-mythical champion from an orphanage background with a record of 37 wins and 32 knockouts. Guy deepens his bond with Gordon and Roman, who are both dying, and faces constant interference from the gangsters who shot his father. The story culminates in the unified heavyweight championship match, where Guy evolves the Tornado Upper into a double version, finally toppling Texon in a brutal war of attrition, fulfilling the dream that the dying men around him invested their lives in. The series closes on an elegiac note as Guy, having reached the top, faces the reality of what it cost the people who carried him there.