[3] Throughout his sporting career, Bang trained for Namyangju City Hall's elite judo squad under his longtime coach and mentor Cho In-chul.

[1] Bang qualified for the South Korean squad in the men's half-lightweight class (66 kg) at the 2004 Summer Olympics in Athens, by placing third and receiving a berth from the 2004 Asian Championships in Almaty.

He lost his opening match to Brazilian judoka and 1996 Olympic bronze medalist Henrique Guimarães, who successfully scored an ippon and an ōuchi gari (big inner reap), at two minutes and twenty-one seconds.

[4][5] When South Korea hosted the 2014 Asian Games in Incheon, Bang culminated his ten-year career medal drought from the international scene to score an ippon victory over 2012 Olympian Navruz Jurakobilov of Uzbekistan for a bronze in the men's 73 kg class.

[6] Two days later, he helped his fellow South Korean teammates outplay their Kazakh rivals to top the medal podium with a gold in the team competition.