Joe Yabuki is the protagonist of the boxing story Tomorrow’s Joe. He is a wandering orphan with a troubled past who discovers a passion for boxing while in a juvenile detention center. Known for his long bangs and his signature worn-out beige coat and red flat cap, Joe is a rude, quick-tempered, and impulsive delinquent who often prefers solitude. Despite his rough exterior and tendency to solve problems with his fists, he is not without a frivolous side and eventually learns to appreciate the friends and rivals he encounters on his journey. He struggles to understand women and typically treats them with a sense of obligation rather than genuine warmth.

Joe’s background is one of instability and deprivation. Having spent his early life moving between orphanages and facilities, he frequently escaped and eventually ended up in the San’ya slums of Tokyo. His life changes when he meets Danpei Tange, a former boxing trainer turned alcoholic who recognizes Joe’s raw, self-taught fighting talent. However, Joe is soon arrested for fraud and sent to a juvenile detention center. It is there that he meets his most significant rival, Toru Rikiishi, a former boxing prodigy. Their intense competition within the prison walls forms the core of Joe’s early drive, with both vowing to settle their score professionally as boxers after their release.

Joe’s primary motivation shifts from mere survival and delinquency to a deep, all-consuming passion for boxing. His desire to fight is based on the concept of living life to its fullest until death, a philosophy that drives his entire career. He is not motivated by money or fame but by the pure, brutal thrill of testing himself against worthy opponents and burning out completely. This is best encapsulated in his famous line about wanting to burn to pure white ash. His role in the story is that of a raw, natural talent who rises through the Japanese and global boxing scenes, his career marked by both spectacular triumphs and profound personal tragedy.

Throughout the narrative, Joe forges several key relationships that shape his development. Danpei Tange acts as his surrogate father figure and coach, struggling to tame Joe’s wild instincts while honing his talent. The wealthy heiress Yoko Shiraki serves as a patron and a complex figure of both support and emotional distance, and she later discovers that Joe suffers from punch-drunk syndrome. However, the most pivotal relationship is with Toru Rikiishi. After the two finally fight as professionals, Rikiishi knocks Joe out to win the match but dies shortly after from the combined effects of weight loss and a brain hemorrhage. This event traumatizes Joe, sending his career into a downward spiral as he is consumed by guilt and grief.

Joe undergoes significant development from a wild, untamed drifter to a disciplined, albeit haunted, warrior. Rikiishi’s death marks a major turning point, nearly destroying him before he finds the resolve to return to the ring to honor his fallen rival. He goes on to fight international champions like Carlos Rivera and Jose Mendoza, earning worldwide recognition. In his final fight against world champion Jose Mendoza, despite suffering from punch-drunk syndrome, Joe endures a brutal fifteen-round battle. Although he loses by decision, the final image is of Joe sitting motionless in his corner with a serene smile on his face, having given everything he had. The ambiguity of his fate—whether he is alive or dead in that final moment—has become one of the most iconic and debated endings in manga history.

As a boxer, Joe is a bantamweight who later struggles with weight control due to a growth spurt. His boxing style is unorthodox and brawling, relying on an orthodox stance but frequently employing a no-guard stance to lure opponents into traps. His signature technique is the cross counter, a high-risk, high-reward punch that adds his opponent’s momentum to his own. He is so proficient that he develops variations like the double and triple cross counter. Joe possesses extraordinary punching power, formidable durability, and an almost superhuman fighting spirit and willpower, allowing him to stand up repeatedly from devastating blows. He is also a genius in the ring, capable of mimicking complex techniques after seeing them just once and adapting his strategy on the fly, as seen when he copied the corkscrew punch from Mendoza or used the ropes to launch counter-attacks.