He was also the main candidate for Jong Gun's successor. After he disobeyed Gun's rule "do not do anything that may get you arrested," by running an illegal betting ring (which, ironically, was what he was using to make money to become Jong Gun's successor.), Gun removed Kimyeong's candidacy.
Kim was first introduced into the series in the illegal betting arc, where he, Jiho, and two others met to discuss the wildly popular ladder betting game. However, he was brought into prominence when Eun Tae, trying to help out Jiho, attempted to fight him in order to convince him to give Jiho his money back. Park Bum Jae attempted to convince Eun Tae not to fight after noticing that they were in "Big Deal" territory. However, this confrontation angered Kimyeong Kim, as he was insulted that Eun Tae thought that he would need his underlings. Eun Tae and Kim immediately begin to fight, with the details of the fight itself being unknown. Eun Tae was later shown bleeding and utterly defeated. As Bum Jae was going to step in and fight himself, Jong Gun arrives on the scene. After being informed that he was no longer a candidate for Jong Gun's successor, Kimyeong Kim reveals that Jong Gun runs an extortion ring, which angers him. Jong Gun then proceeds to brutally defeat Kimyeong Kim, ripping out his teeth in the process. Later, Kimyeong Kim is shown in a Juvenile Detention Center, vowing to himself that he will kill Gun.
Kimyeong Kim is the third most proficient fighter to show up on screen to date, after Jong Gun, who defeated him, and Joon Goo, Jong Gun's equal.
Although it may be argued that Park Hyung Suk may be faster, Kimyeong Kim defeated Lee Eun Tae, who is Hyung Suk's equal, and, as stated before, was the second to visibly injure Jong Gun.