Jiro Shioya

An anime original character Jirou is a delinquent teenager who rides a motorbike. He lives in a very poor and rundown boxing gym with his father and sister. The first time we get to see Jirou is when he appears with his biker friends disrupting the kids playing with Joe which annoys Joe. Joe tease Jirou which then Jirou tries to run Joe over with his bike, but Joe does a flip which causes Jirou to lose his balance so he crashes. He then gets frustrated at Joe where he tries to fight him but Joe just dodges his punches with no problem and teases him even more so he then flees. He then meets Joe another day on a bridge where he then tries to attack and hit Joe once more, but Joe catches his punches and dodges them. Joe tells Jirou how he should have his shoulders and elbows when he punches and then tells Jirou to hit Joe again where then Jiro's punches are sharper and a bit better. Joe tells Jirou that he has potential and Jirou gets surprised and asks surprisingly if he really means it where Joe then says yes. Jirou then comes home to the rundown gym and tells his sister and father that he's thinking of selling his bike and to become a trainee at his father's gym which makes both his sister and father happy.