Joe Yabuki arrives in a poor Tokyo district and catches the attention of Danpei, a former boxer who sees promise in his movements. Joe initially resists the older man’s plans. Trouble with the law eventually brings him into contact with a formidable boxer, Toru Rikiishi.
Danpei sees training Joe as a way to return to boxing after his own career collapsed. Joe, meanwhile, does not begin as a willing pupil. Their partnership has to survive that mismatch before instruction by postcard and the prospect of a serious rival can change his interest in the sport.
Danpei’s own battered body makes his proposal a difficult one to sell. In an early encounter he is wrapped in bandages while addressing the much younger Joe. He wants a pupil who can give his boxing knowledge a future, but Joe sees no immediate reason to accept the role; their unequal needs matter as much as the older man’s eye for talent.