Jo Jin-gab – Starring Kim Dong-wook

Male in his late 30s, nickname Jo Jang-poong, former PE teacher, current level 7 civil servant.
He is a level 7 civil servant of Korea. He is a former judo athlete on the national team with a promising future. However, he gets rough while protesting to a referee about a fixed match. He ends up breaking his ankle and getting kicked out of the judo association for calumny and assault. After wandering for a long time, he gets a fresh start as a PE teacher. However, while working with troubled students, he blows up at the board president’s son and gets branded as an abusive teacher and fired. That’s when he gets his nickname Jo Jang-poong. After 12 tries with his brain that isn’t wired to study, he finally becomes a level 9 civil servant, but his bad luck lands him at the Ministry of Labor. He lives as if he doesn’t see or hear anything and he gets promoted to level 7 before he knows it. The Ministry of National Defense isn’t the only group that has to do as they are told. He becomes a level 7 labor inspector, a job everyone tries to avoid.
One day, he goes to inspect a delay in payment of wages and meets him. It’s a former student of Jo Jang-poong’s, who feared nothing in the world at the time. When the student he couldn’t protect shows up with the saddest face ever, Jin-gab wants to look away. He tries to tell himself that a single labor inspector can’t change the reality, but when he sees his former student getting pushed around by those with power, he swings his fist before he can catch himself. The damage has been done. He either has to catch the bad guy or he will be ruined. He is a special judicial police officer. He’ll catch the bad guy if it’s the only thing he does. The former student that runs a PI office and former abusive teacher that has become a labor inspector get together to get the money alumni got jobbed out of back.

Cheon Deok-gu – Starring Kim Kyung-nam

Male in his late 20s, head of the popular group at school when he was young, currently runs “Gabeul”, a PI office.
Having been poor as he grew up, he had an iron fist and strong ego, becoming head of the popular group of bullies at a young age. The older boys that seemed like they belonged in a gangster movie looked cool. When he becomes their age, he realizes that he has to bluff to look cool. However, the actual head of the group was someone else. It was Yang Tae-su, the board president’s son. They say they’re friends, but Deok-gu is actually just Tae-su’s gofer. He can’t help but rough up whomever Tae-su isn’t happy with. If he doesn’t, he’d be the one getting roughed up. Right about then, they get a new dean called Jo Jang-poong. He picks out the strongest kid of each class and makes sure to scare him. Jang-poong is a weirdo. Deok-gu never knew he’d look up to a teacher even when Jang-poong motioned at him with his finger, saying he’d let Deok-gu go if he could beat him. It was cool to watch Jang-poong use judo skills to put each student to the ground. Jo Jang-poong is keeping an eye on him when he slowly finds the potential of a hero within himself, but ends up getting in trouble because of Tae-su again. Jang-poong gets branded as an abusive teacher and disappears from the classroom without a trace. When the teacher that had disappeared into thin air shows up 13 years later, Deok-gu becomes his secret investigator without asking any questions.

Woo Do-ha – Starring Ryu Deok-hwan

Male in his late 20s, lawyer at Myungsung Group, the new chairman of One Heart Foundation
He is the new guard of the safe at the scholarship foundation that moves to Guwon-si. A top elite takes the place of a hardheaded man with power. He’s a lawyer turned prosecutor and the head lawyer of Myungsung Group’s main office. Do-ha used to watch Tae-su’s back when they were in school and clean up after his mess. It’s no surprise when Tae-su also moves to Guwon-si. He has caused trouble and is sent to TS, a small subsidiary, as director. As the son of the owner, he causes a huge fluctuation in their stock. People wonder if Do-ha, who was sponsored by Myungsung with a scholarship, is sent to clean up after Tae-su once again. However, he surprisingly treats Jin-gab and Deok-gu with favor. He even assists Jin-gab in tracing Tae-su’s wrongdoings while pretending he doesn’t care or to help Tae-su. When Jin-gab asks why, Do-ha gives him a simple answer. “Who would like a world in which people like Yang Tae-su uses his power? I’d like to see someone like you win for once. You probably don’t know, but I liked you.” It’s the truth. He liked that people like Jo Jang-poong existed. If people like him could win, he wouldn’t have to live like his father. He didn’t want to live like his father. He wanted to be a success. Watching Tae-su’s back, he was able to study with Myungsung’s money and come this far. This smart and ambitious man has a plan of his own. He wants to change Myungsung Group’s management system and have a professional businessman run the group. He wants that businessman to be himself. He can get rid of Tae-su at the last moment. Jo Jang-poong will be able to play the perfect role in doing that.

Yang Tae-su – Starring Lee Sang-yi

Male in his late 20s, only son of the CEO of Myungsung Group, director of TS.
He is the only son of the CEO of Myungsung Group. He was once the symbol of 3rd generation chaebols abusing their power for assaulting someone while being drunk, but he lost the title when other chaebols caused trouble regarding ramen and peanuts. He totally lacks empathy, is self-centered and couldn’t be more childish. He doesn’t consider the things he’s done and can’t understand why the world points fingers at him. He is truly lonely and feels like he is being wronged. He is a pathetic troublemaker, but the problem is that he holds way too much power. Too many people get hurt by his thoughtless actions. Measures are being taken to give the entire group to this immature boy. As a part of the plan, he is sent to TS, an unlisted system integration company, in Guwon-si. They made it look like he is being punished for getting drunk and abusing his authority against the group’s new lawyers, but it is actually to lay out the foundation for succession. They bulk up the company through internal transaction among subsidiaries and Tae-su is to marry a prosecutor chosen by his father. This is what causes him the most stress nowadays. He is going nuts, trying to keep the ugly prosecutor with a huge ego. To add to that, Jo Jang-poong keeps getting on his nerves.

Joo Mi-ran – Starring Park Se-yeong

Female in her mid-30s, Jin-gab’s ex-wife, detective in the intelligence division.
She is a chic, realistic woman of principles. Everything seems tenuous to this detective that has been divorced for 13 years and goes through the motions each day. She met Jin-gab in university when they were both judo majors, fell passionately in love, got married at 22, had a child and gave up her life as an athlete. She loved how honest and just Jin-gab was and his kindness in helping others. However, this became the reason they argued after getting married. During an important match, which would determine his qualifications for the Olympics, he gets in a fight with a referee over someone else’s matters and gets thrown out of the association. That’s when she asks for a divorce. He begs her not to leave and promises never to do anything like that again. She becomes a police officer with her judo skills through a special employment program, since her husband has become jobless. Jin-gab pulls himself together and becomes a PE teacher. She thinks it will all be okay when he gets in trouble again. He is on the 9 o’clock news for assaulting his students. He also loses his job. She can’t take anymore of this. He is who he is. So they get divorced after being married for 9 years. 13 years later, Jin-gab is a civil servant, a job that doesn’t fit him at all, and turns into a totally different person that they have nothing to argue over. He’s been a faithful parent to their child for 13 years and a good ex-husband. He sends half of his paycheck to her as child support and she couldn’t ask him to be a better supporter in raising their daughter. He texts her on special occasions and sends her health supplements. People say they should just get back together, but she doesn't think so. When a dish shatters, you don’t put it together and use it.