Main ;Park Hyung Suk/Park Daniel/Keisuke Hasegawa : :Park Hyung Seok is a naive, short, obese and non-conventionally attractive high-school student who was bullied relentessly by Lee Tae Sung every single day. Before transferring to Jae Won High School to escape the bullying, he awakens one day with a tall, athletic and extremely attractive body next to his obese one. Realizing that he can switch bodies after one is sleeping, with his new body, he starts a new life. During the day he goes to school and makes friends and rivals, thanks to the attractiveness and surprising strength of the second body and in the night he works at his local Mart seeing how the world treats people differently due to looks, with the 1st body. After an incident due to Jiho he goes into a coma and finds out his real name, or specifically the second body's real name, is Lee Jihoon(Lee James) a former prodigy both academically and physically who mysteriously disappeared. He is threatened by Choi Dong Soo(Choi Charles) to stop searching for him. however Hyung Seok arrives at the conclusion that he and, consequentially, DG know about his body but to reveal it he will face the 4 major crew. ;Lee Eun Tae/Vasco/Basco : :Lee Eun Tae has a reputation of being a
Robin Hood-like figure, defending the weak and bullied. A childhood friend of Park Bum Jae, he leads Burn Knucklesa gang which punishes bullies and other wrongdoers. Despite his tough exterior, he is sweet and seeks the friendship of those he considers good. ;Hong Jae Yeol/Hong Jay :A quiet, wealthy, and mysterious character who uses the
systema and
kali martial arts. ;Lee Jin Sung/Lee Zach/Ryūsei Kitahara : :Lee Jin Sung is a boxer who was aggressive towards everyone except his childhood friend, Kim Mi Jin, whom he loves. Mi Jin dislikes violence, so Jin Sung stops bullying and becomes more patient. ;Kim Mi Jin/Kim Mira/Mizuki Sakane : :Kim Mi Jin is compassionate, patient, and observant, and sees the good in everyone. Seong Yo Han and Lee Jin Sung were in love with her.
DG/Diego Kang/James Lee :Famous K-pop star who has some hidden past identity, the original James Lee. One of Charles Choi's associates, who seems to know about Daniel's ability and is modeled on
G-Dragon. He is most probably the strongest character in the First Generation after Kitae Kim.
Kitae KimIntroduced as the illegitimate child of powerful gangster of korea(Gapryong Kim) and also half brother to Jake kim. He lived in mexico for some years and became a cartel leader. and now is the villain in the story alongsidejames lee ;Johan Seong :Zack and Mira's childhood friend. Bullied because he was poor and his mother was going blind, he had a crush on Mira. His mother's mental state deteriorates and a local religious figure persuades her to join the God Dog cult. Johan takes over the cult, taking its mascot as his own. He aids Jace in Cheonliang and fights with Jin before joining the White Tiger Job Center under Tom Lee. Left the group and becomes allied with Charles Choi, but his sight was still worsening. He picked up other martial arts as his arsenal. ;Eli Jang/Jang Hyun :The single father of a baby girl named Yenna, the daughter of his teenage sweetheart Heather. Jong Gun had his eyes on him for his fighting prowess but also because Eli created the original Hostel. Currently under Eugene's control. ;Samuel Seo :An executive, working for the workers. Previously from Big Deal and was known as Big Deal No.3. He was initially on Alexander's side, then takes over the affiliates that has fallen. Initially allied with Eugene, but turned after a deal with Johan. His goal is to become "King" and will do whatever it takes to do so. ;Park Ha Neul/Park Zoey/Kagawa Mirei : :Park Ha Neul is a beautiful girl who tried to use charm to get what she wanted. After Park Hyung Seok's original body saves her from a stalker, however, she develops romantic feelings for him. ;Choi Soo Jung/CrystalChoi/Akari Nerima : :Choi Soo Jung is daughter of the HNH company chairman, also has two bodies. First, an overweight student who transfers to the fashion department of Hyung Seok's school, she lives in her original body during the day. Her different treatment leads her to believe that the world judges those with a different appearance unkindly. Soo Jung sees the handsome Hyung Seok as an egotistical bully (based on his looks) and prefers the other Hyung Seok's personality. :
Supporting ;Hyung Seok's mother/Mrs. Park Seon Hul/Mrs. Park Kim :Hyung Seok's single mother is an old, hardworking, and patient woman. After seeing Lee Tae Sung bully Hyung Seok, and her son yelling at her, she transfers him to Jae Won High School. She works twice as hard to enable Hyung Seok to attend Jae Won High, folding and selling empty boxes and working part-time waiting tables. More than anything, she wants Hyung Seok to be happy. As he matures, Hyung Seok begins to appreciate and help his mother. ;Park Bum Jae/Jace Park :Park Bum Jae, the second-in-command of the Burn Knuckles, is a childhood friend of Lee Eun Tae and helped him overcome his
fear of needles. ;Pyeon Deok Hwa/Pyeon Duke/Hinto Kon : :A short, plump student and an aspiring rapper who was bullied by others and rejected by producers. When he meets and collaborates with Hyung Seok, he gains confidence, begins streaming on TV and becomes famous. In the middle of the webtoon, he became a famous rapper. ;Park Jiho/Park Jiho :Bullied at J High until Hyung Seok takes him under his wing, he is obsessed with power and societal standards. Ji ho shows signs of an
inferiority complex and goes to juvenile prison for the attempted murders of Hyung Seok Park and Gong Yeong Hun. He becomes mentally ill in prison and is influenced by Kim Gi Myeong. He commits suicide after a fight with Hyung Seok, while being haunted by his hallucinations. ;Lee Tae Sung/Lee Logan :A big, strong character who bullied Hyung Seok Park in his former school; after Hyung Seok moved to Seoul, Tae Sung did too. Hyung Seok stands up to Tae Sung in his original body, and they reach an uneasy truce. Tae Sung is expelled after assaulting his advisor. ;Jin Ho Bin/Bin Vin/Takahito Saitama : :Arrogant, he says he is better than everyone else and dislikes Hyung Seok and Duk Hea. He fears losing his sunglasses, and loses control when they are removed; this is later explained by his
polycoria in one eye. ;Kim Mi Roo/Kim Mary :A pretty, blonde girl who is friends with Jin Ho Bin and is known in Cheonliang (her and Ho Bin's hometown) as the Empress of Two Seconds because she defeats opponents in a fight in two seconds. She hides her past as overweight but skilled in Judo and receiving plastic surgery. ;Kim Yoo-I/Kim Yui :The leading streamer on Paprika TV until Park Ha Neul joins the website. When her boyfriend learns from Lee Jin Sung that she flirted with Hyung Seok, he beats her until Jin Sung stops him. She then develops feelings for Lee Jin Sung. ;Lee Hyun Do/Lee Doo :Jiho's main tormentor, he stays around Lee Jin Sung and Park Hyung Seok mostly to increase his popularity but helps them as needed. A streamer on Paprika TV, Park Tae Joon collaborates with him to taunt Shin Dae Hoon; they are caught by his gang before being bailed out by Lee Eun Tae, Lee Jin Sung, and Park Hyung Seok. He later sometimes appears as Hyung Seok destroys the Workers, once as part of Hwang Jae Won's clean-up crew, then became Hannya of Sōma Mitsuki's crew. ;Park Tae Joon :An Executive Manager of PTJ Entertainment who will do almost anything for fame. ;Leonn Lee :A mysterious freshman who is revealed to be a girl, her character is a
tsundere. ;Joy Hong/Hong Jae Hye :Jay's little sister and a model who has a crush on handsome Daniel and enrolls in J High to see him more often. ;Nam Su Lee :A nerdy classmate tasked by Zack to buy shoes for him. He buys a ring and says that Daniel is poor and has no fashion sense, and Jay gives Daniel a collection of expensive clothes. ;David, Dylan and Sarah Park :Daniel's cousins. Dylan wants to be a rapper, and is Duke's fan; David, a college student, is the star of the Park family, being enrolled into a prestigious university; Sarah, Dylan's sister, has a crush on handsome Daniel. ;Hong Ki Tae :Jay's older brother. The polar opposite of Jay. ; ;Alexander Hwang :Samuel's associate, who disappears. ;Like What and So Funny :Runaway girls who are first forced into prostitution and then begin streaming to earn money. Currently under Sally Park's care. ;Warren Chae :Speaks in broken sentences before joining Daniel in his mission. He regains his speech later on and joins Eli in his endeavors. ; ;Sally Park :Usually seen with Warren Chae, she is an orphan who lives in an abandoned building inherited from her grandmother in the US. ;Max Kang and Derek Jo :
Tteokbokki sellers and club promoters. The power duo of Hostel. ;Olly Wang :Heather's friend and schoolmate. Betrayed Hostel after he wasn't included, which nearly destroyed the fam. He created his own Hostel from scratch. Commits suicide after learning the source of his inability to feel pain, his guilt over Heather's tragic end. ;James Gong :Jiho's psychotic, sadistic bully. Resurfaced after escaping the hospital he was, joining initially Olly's Hostel, then left with Jasmine and Olly's orphans aboard a coaster. ;Jasmine Huh :Daniel's classmate, who is a pathological liar. She lives with James and the child soldiers trained by Olly trained, riding a stolen bus. ; ;Jong Gun/Jang Dong Gun :Crystal Choi's sadomasochistic gangster bodyguard, who is an extortionist. Once a Yakuza member, he destroyed the clan after he got bored, and became Charles Choi's money collector. After Charles Choi commits suicide, Jong Gun is charged after taking the fall for his boss. ;Joon Goo/Goo Kim :A fighter who frequents juvenile centers and succeeds Jong Gun in his extortion racket after Gun loses interest in it. Initially appears as a paid merc by his own cousin. ;Jerry Kwon :Jake Kim's number-two, known as Jake Kim's Sword, who cares for the cat Leon. Usually gentle, except when following Jake's orders. ;Jin Jang :Johan's faithless lieutenant, who begins spying on J High and plots to pit the students against each other. He later revives his K House gang from the God Dog ruins. ;Kouji/Ko Woo Ji :A hacker, he dupes the illegal
toto operators and hacks the security feed of the store at which Daniel works. He wants to hack onto Jay's systems. ;Charles Choi/Elite :Crystal's father, an executive who worked at a convenience store until he created 4 crews with Jong Gun and other geniuses. He raised 10 geniuses (Group of 10 people who are extremely capable in their respective fields, DG and Kouji among them). ;Steve Hong :Ki Tae, Joy and Jay's father, an executive who knows Charles Choi. He becomes Daniel's secret ally to take down the four gangs. ; ;Oliver Jang/Jang Udon/Woo Dong Jang :Debuts in a new group, Inspirit. Was once in relationship with ARU, until she betrayed him. Became a perpetual trainee until Daniel and Joy joins the crew. ;La Sol/Ra Sol :Another perpetual trainee alongside Oliver who becomes a trainer. ARU's friend, was reduced to her status after ARU rose above the rank. ;ARU :Oliver's ex-girlfriend and a star who is caught in a
casting couch situation. ;Tom Lee :One of Charles Choi's 10 Geniuses and owner of a private security agency, White Tiger. Prefers fighting on boxer shorts. ;Justine Peng and Chuck Kwak :Two illegal Chinese immigrants rejected by Jake Kim but later accepted by Olly Wang. ;Vivi :Chinese woman who flees to Korea to escape her Chinese drug cases, the head of a powerful family who built a club and hotel to cover her drug addiction. She later returns to China with Xiaolung. ;Xiaolung :Vivi's servant, who becomes a
eunuch to remain close to her. He returns to Korea after taking Vivi home and joins Eugene. ;Alexander Kwang :Covers up his rackets by imprisoning promising
vloggers and forcing them to work for him, but is foiled by Daniel. Disappeared afterward, last seen as part of a clean-up crew. ;Sofia :A muscular Russian woman, Steve Hong's bodyguard, who trains Daniel to reduce his weight. ;Eugene :Head of the gang for which Samuel works, who issues deceptive invitations in Olly Wang's name. He invites the other gangs to unite against Charles Choi; Jake, Justin and Chuck accept, and Johan and Eli decline. He Apprentices Daniel, but does not trust him. He has a twin brother named Yuseong, who was the mysterious silent capped character with black VVIP badge. ;Yuseong :Eugene's twin brother, a silent but emotionally unstable person. ;Hudson Ahn, Jacky Lee and Channing Choi :Leaders of the Ansan Public, a group trying to establish a footing in Seoul. Join Jiho and Darius Hong to form the James Lee Crew, and return to Ansan after being beaten by Daniel, Zack and Vasco. Hudson is their leader, Jacky is the most agile, and Channing is a sadist. ;Mitsuki/Neko :Leader of the 2nd affiliate and emcee of the underground death-match club, who has feelings for Sinu. ;Ryūhei/Nōmen :Acquaintance of Mitsuki who wears a Nōmen mask. His name was Ryūhei. ;Hyottoko and Daruma :Two masked men; Hyottoko is a sumo wrestler and discharged JSDF soldier named Kazuma Sato, and Daruma is a former Yakuza named Kenta Magami, who had grudge against Jong-gun for destroying his clan.
LinemanHe is one of the main fighters in the Big deal, under Jake kim. And he is trained by Lightning choi of Gapryong kim fist gang
Sinu HanThe first leader of Big deal. He starts Big deal to protect his street from other thugs, Which is later taken over by Jake kim
Jinyoung park / JinYeong parkHe is a medical prodigy and skilled fighter, who is main member of Gapryong Kim's Fist Gang. He has a ability to copy any fighting skill he sees once. He is also the uncle of Daniel Park who inherited his copy ability.
Gapryong KimHe was the most influential Gangster who fought against Shingen Yamazaki and his clan with his Fist Gang and saved Korea. He tried to become a congressman but died even before achieving it. He is also the father of Jake kim and Kitae Kim ==Themes==