In "Ashita no Joe: Fighting for Tomorrow," Joe Yabuki, who experienced a difficult childhood marked by frequent moves between orphanages and relentless bullying, developed a hardened demeanor and a profound distrust of others. After fleeing that unstable environment, he turned to a life of delinquency in San'ya, a dilapidated area of Tokyo, where he survived by fighting and challenging anyone he pleased.
Danpei Tange, a former boxing trainer now battling alcoholism, recognized Joe's raw fighting ability and tried to guide the unruly youth. Despite their volatile interactions, a strong connection formed between them as both cared for the other homeless children in San'ya.
Despite his attempts to change, Joe's rebellious behavior led to his arrest for minor offenses. In prison, he encountered lifelong friends and rivals, including the boxing prodigy Tooru Rikiishi. Joe frequently challenged Rikiishi, but his brute force style consistently fell short against Rikiishi's disciplined boxing techniques, resulting in repeated defeats. However, Joe eventually delivered a shocking knockout punch to Rikiishi, earning the latter's respect and a promise to face each other again in the professional ring.
With boxing now providing him a sense of purpose, Joe approached life with renewed vigor. As he progressed through Japan's amateur and professional boxing circuits, he faced numerous setbacks and injuries. His dedication to the sport became his sole focus, leading him to question whether a life devoid of boxing could have any meaning.