ジャンクドッグ, Junk Dog, "Gearless" Joe, JD, Big Joe

Junk Dog (ジャンクドッグ Janku Doggu) is an underground Megalo Boxer from the outskirts of town whose real name is unknown, he is forced to throw fights to earn money for his crooked manager. He initially fights with old Gear that is constantly in need of repair. He takes on the name "Joe" (ジョー Jō) when he has a Citizen ID forged in order to enter the Megalonia tournament. He later takes on the ring name "Gearless" Joe (ギアレスジョー Giaresu Jō) as part of a gimmick to rise in the rankings quickly, fighting without Gear against Gear-equipped opponents. His counterpart in the original Ashita no Joe is Joe Yabuki.

Source: Wikipedia