Kim Han Gyul is a former school colleague of Jae Gu Song. He often bullied Jae Gu in his past school and when he noticed that Jae Gu was attending Wild's High began to torment him again. He is a freshmen at Goo Ra High who specializes in Kick Boxing.
Kim Han Gyul hair is crimson red in color and is spiky on the top and the sides of his head are shorter and kept neat. His eyes are black in color and are small often considered "beady" by those who first encounter him. He has dark colored eyebrows which always make him look angry or frustrated. In terms of height he is a few inches shorter that Jae Gu. He is often seen wearing either the Goo Ra High uniform which consists of a black shirt, tie, pants, shoes and white collared shirt. When training he wears the green and yellow tracksuit worn by all Goo Ra High students. In his battle with Jae Gu in the Wild's League he wears a green tank top and red boxing gloves with the Goo Ra High tracksuit bottom.
Kim Han Gyul is cruel and ruthless. He is selfish towards everyone even to his own friends. He shows no remorse after he causes harm to Jae Gu's siblings or to Jae Gu. When confronted on matters by his fellow students or coach he either cowers or lies but when confronting Wild's students he acts arrogant. Nothing in his mind should stop him from getting his way and anything that makes him look bad needs to be removed. He's foul mouthed, egotistical and filled with self-worth. Most of his boasting is often hot air and equals to nothing when he is confronted. After being defeated by Jae Gu he still remains angry and bitter towards the man but stops calling Jae Gu "Worker Song" the old name he called him in the old school.
He went to the same middle school as Jae Gu Song and bullied him throughout his school term. Calling him names such as 'Slave Song', yelling foul mouthed insults at him any chance he got.
In Goo Ra High he is regarded as a first class applicant who specializes in kick boxing. Although he is a capable fighter he often resorts to under-handed methods to win fights, bringing weapons when confronting people, grabbing objects to hit people with even if they can cause serious damage. In the fight with Jae Gu he uses his elbow to damage Jae Gu and make it difficult for him to see in the battle. Throughout the battle he does many under-handed techniques many which are considered illegal in official matches.