Mercenary Enrollment Wiki

Yu Ijin is the main protagonist of the Mercenary Enrollment manhwa (Other Name: Teenage Mercenary, Ipak Yongbyeong). The story starts when Ijin, a young mercenary and victim of a plane crash, reunites with his family after a decade. He tries to be a normal high school student and protect the family he had not seen in years, but criminals and kidnappers thwart his path.He is also has shown to use Krav Maga, an a military self-defense and fighting system developed for the Israel Defense Forces.[1] This manhwa has interesting themes such as persons orphaned by war, the importance of families and the sad of use of children as child soldiers. It focuses on child abuse due to war and the robbed childhood of young children (see chapter 29 when Ijin is deeply thinking about being "wronged" by being made to fight for 10 years). It also has good lessons of "STRONG should protect the WEAK" where Ijin protects his sisters and friends from bullies, Cha Dusik from other gangsters and 032 from other mercenaries so on. The manhwa also highlights issues of violence against women (Ijin has to defend and fight for Yu Dayun and Shin Yuna, and then Shin Jihie and even for Cha Seoha)


Yu Ijin after school

Ijin in camouflage

Yu Ijin is a tall, grey haired boy in his teens. Although he is portrayed with a slender build, he is at least as strong as soldiers of the Special Military Force. He currently outclasses everyone in terms of combat skills introduced in the story. In his mercenary days, he wore olive fatigues and a shemagh to conceal his face. He is mainly seen wearing school attire, casual wear and his formal suit (after becoming a bodyguard trainee). When angry, his face is expressionless but he is portrayed with reddish irises of the eyes and a blue aura surrounds him. Ijin's most powerful features is his EYES. When ever Ijin is really happy or peaceful or worried his eyes are closed or hidden from view.


As a consequence of his grueling training as a mercenary, Ijin is a composed and reserved person who never panics in the face of danger. He is very astute and decisive. Ijin doesn't suffer from PTSD, although he occasionally has nightmares of the plane crash that orphaned him. He slowly learns about the concept of love and affection after reuniting and spending time with his family, which he starts to value more than anything else. After he begins to attend high school, Ijin is able to make friends and frequently joins them to play Legends of League (MOBA) at the internet cafe. He is noted to be inept at video games, but is unusually adept at actual combat.


Ijin is portrayed as an ideal fighter, extremely good looking, physically strong, very well trained in battle tactics and strategy planning including espionage, and far more intelligent than his age of 19 years and has a code of honor. He is very gifted in both IQ (intelligence quotient) and EQ (emotional quotient). He strongly believes to repay his debts and kindness done towards him, as well as protect the weak if he sees them being abused, whether family or friends. Due to quick adaptation from battlefield to a normal school life, he has almost no school issues or family issues and hides his battlefield memories quite well because he wants a normal life with family. But when required to do things in a professional manner he can be as calculated as any highly trained adult far older than his own age such as 36 year old Lt. Hamchan, who rescued him from his mercenary life, and so many others such as his own grandfather who have no idea of Ijin's background.

There are so far only 2 instances in which he has shown extreme emotional distress from nightmares, showing he suppresses his memories but his dreams are tormented at times (1) when he remembers his plane crash with his parents at 9 years age and (2) when he was ordered to kill a mother and young girl while working as a mercenary (it is not known if he actually did kill these innocent people)

He is the strong silent type, who speaks less and listens more. He almost never shows his emotions when fighting and there are countless times when he is shown to be simply listening and thinking about things he sees or hears (speech balloon with lots of dots are shown numerous times in every chapter)

Notably when Shin Yuna and Yu Dayun got kidnapped Ijin bluntly stated atleast 3 times that he wasn't trying to rescue Yuna, just Yu Dayun, his own sister. Ijin realizes that he cannot have the LUXURY of romantic love until his family members (grandfather and Yu Dayun) are completely safe. Maybe for this reason he tries to avoid becoming close to Shin Yuna and purposely kept her at a distance. Thats why Ijin, actually PROBABLY DID fight to save BOTH Shin Yuna and Yu Dayun, but he did not want to get Shin Yuna to become to attached. However latest chapters show there maybe a blossoming romance between the two people.

Therefore Ijin is mostly shown in IDEAL manner although there are sometimes when he is shown more REALISTICALLY with faults as well. In the early chapters, his behavior towards his classmates Shin Yuna and Koh Sukjoo is almost like a superficial, detached friend (even though they had apologized for suspecting him to be an imposter posing as Yu Dayun brother). He seems to only contact Sukjoo when he needs some work done with tracing people on CCTV in public areas only recently has become more friendly with Sukjoo. Also, Ijin NEVER properly thanked Sukjoo who got himself stabbed in order to protect Yu Dayun.

Ijin is extremely conscious of his own privacy, and for his family and school life (infact he was so upset that Shin Yuna and Koh Sukjoo were prying into his family life that he was very rude and blunt to Shin Yuna because she had ordered Sukjoo to check up on his past life and almost destroyed his relationship with sister Yu Dayun. Ijin will probably continue to go to great lengths to protect his family life and privacy and just like for case of shin Yuna (the prettiest girl in class and daughter of very wealthy family) is being kept at distance because she almost destroyed his family life by rash behaviour in chapter 15 and 16, He will probably be like this to to anyone else who tries to mess up his family even if they are a possible romance

Because he is secretive, therefore he replies in almost terse statements to questions. He also declines invitations to dinners where he feels he might be indebted to people, preferring to eat with people at PC Bang or Convenience Stores or at home. It is INTERESTING that ijin's sister and grandfather almost never want to ask about his previous life but other people are interested (probably due to witnessing his fighting skills).

Despite being so strong he does not want to indulge in becoming a "bully" or a "boss" in school but rather wants to blend peacefully. Intelligent people usually hide their emotional scars and it's true for Ijin also. At a young age he has probably experience being abandoned, manipulated, trapped or controlled by persons in power or wealth. It seemed that he had rescued many people during his mercenary days but the only one to rescue him in turn and help him reunite with his own family is Lt. Hamchan, hence Ijin is especially close to him. Ijin has a strong sense of being "wronged" and his thoughts at the end of Chapter 29 are extremely influential in conveying this. Also there one single panel (Chapter 44) in which ijin had protected a lady Shin Jihie at almost the cost of his life and she walks away without being enthusiastic in her thanks. The panel shows subtle but noticeably annoyed Ijin

Interestingly, politicians like the Senator Kim and rich businessmen are not shown in a particularly good light in the manga, while military is portrayed more favorably. Gang bosses are also not shown very nicely except one person Cha Dusik who is "somewhat" friendly with Ijin. However, Ijin on the other hand kept Cha Dusik at a arms-length distance (until very recently), despite that Ijin had to borrow Cha's motor-bike several times to, including to rescue his sister Yu Dayun (chapter 17) and even to battle another mercenary 006.

This is why he kept aloof from Cha Dusik because Cha Doosik used to be close to Senator Kim. Also, Ijin seems to be very hesitant and distrustful of the Shin family in the beginning including Shin Yuna, Shin Jihie and even the grandfather of Shin family. His attitude changes when he realizes that Shin Yuna’s father had met him during mercenary days and was a kind man who treated him like a son. Even when Ijin starts work part-time as a body-guard for Shin Jihie, he appears to be aloof initially

Ijin’s unconcerned behaviour towards a cute, younger, naive rash mercenary comrade 032 (17 years old, hence 2 years younger than Ijin) who was blleding from gunshot wounds while ijin was calmly offering my food to eat. This in sharp contrast to how he decides to go out of his way to protect Lt. Hamchan at the cost of his own life “because he did not wish to live with regret of not having helped”. 032 was actually depressed when Ijin was rumored to die. But Ijin later on went out of his way to rescue 032 and showed that he does really care about people so much he is even willing to risk his life


When Ijin was nine, he and his parents were involved in a plane crash. Although Ijin survived, he was orphaned and was stranded from his remaining family. Eventually he was taken in by an unnamed group. Ijin underwent harsh training, and he worked as a top class mercenary for about eight years, serving in the harshest battlefields across the world.

Later, during a rescue mission, he saved a RoK major named Kang Hamchan, his team and a doctor Andrian Ken. Kang Hamchan traced Ijin's family and helped him retire. Ijin underwent a six month orientation from Major Kang to help him adjust to civilian life. He's currently living with his grandfather and his sister in Seoul. Aside from attending Shinan high school, Ijin works as a part time bodyguard at the SW group's security team, along with fellow classmate Koh Sukjoo.

In Chapter 1, we are clearly told by Ijin himself, that he was 9 years old when he suffered a plane crash and through his sister, Dayun we learn that he has returned home after 10 years.

In same Chapter 1, When discussing with Lt. Hamchan, Ijin also tells he was on the battlefield as a mercenary for 10 years

Plus, also in Chapter 1, Ijin had a six month orientation with Lt. Hamchan before reuniting with his family and ALSO forged BUT official documents were being created by the government to give him suitable cover to reintegrate normally into school and family life (also in those 6 months Lt. Hamschan MUST have been possibly MONITORING if Ijin has any serious psychological issues that could cause problems for his smooth integration)

In Chapter 20, Ijin’s fellow mercenaries call him JIN. Then, in Chapter 24 , Shin Yuna’s grandfather mentions that Shin Yuna’s father Shin Ingook was rescued by Ijin three(3) years earlier from the date of Ijin’s this school meeting with Shin Yuna’s grandfather. This fact is further confirmed in Chapter 26, (when Ijin is selected as best performer in SW training). We learn from Shin Yuna’s grandfather that he was identified with code name” Jin” when he rescued Shin Ingook

In Chapter 10, Ijin hacked Cha Dusik's computer (a leading crime gang boss with a good heart)

In Chapter 31, Head Mercenary of the camp "Mad Dog" remembers being wounded by Ijin (blinding him in one eye). We also know he is the head mercenary because in Chapter 55, his face is shown when 032 is referring to him with Ijin

In Chapter 50, a female mercenary named Krasilla states that the mercenary JIN disappeared about 6 months ago

In Chapter 52, Ijin has a nightmare from remembering trauma of killing a young girl and her mother, during a mission.

In Chapter 61, Ijin correctly understands the complicated financial transactions between 2 companies collaborating with each other to pressurize Cha Seoha to work for them (thus avoiding bankruptcy) while even though being older, Cha Seoha does not realize this.

in Chapter 72, Ijin seems to understand Lewis Bailey’s (an American’s) discussion with Yuna, hence rescues Yuna from an embarrassing situation. We also know that Yuna and Sukjoo spent time in the USA so they can understand English.

So from information above, we add the situation up and arrive at the following conclusion

a) Ijin is ATLEAST capable of understanding two (2) languages Korean and English and probably one other language of the foreign country where he was raised as a orphan mercenary.. Since countries where English is normally spoken are mostly developed countries with good security and absence of war, such mercenary camps using " ORPHAN child soldiers" are unlikely to be operating from inside a developed country (Infact ORPHANS as CHILD SOLDIERS are used in war affected countries, so this point is realistic)

b) Ijin was ATLEAST 15.5 or 16 years old when he deserted the camp and operated as JIN, till he was rescued by Lt Hamchan at 18.5 or 19 years. When rescued by Lt Hamchan, and with 6 months orientation, he is now probably already 19 or 19.5 years old. So Ijin picked up all his battle skills (additional language ability, computer hacking skills, physical fighting and tactical analysis, leadership skills, sophisticated financial knowledge) in 6 years from age of 9 onwards till 15-16 years, when he felt confident enough to desert camp, (even at that age he was better fighter than the head mercenary at the camp "Mad Dog", having blinded him in one eye) AS WELL AS, kept his new identity so skillfully secret that the camp did not suspect that "JIN" and "001" are actually the same person. Also, during this period of 9-16 years of age, he had also killed a mother and young daughter daughter which deeply traumatized him and made him attack the Head Mercenary, as well, as abandon his camp. Ijin must have already killed countless persons but this killing of an innocent mother and her daughter was VERY DISTURBING for him.


Yu Dayun (Younger Sister)[]

Ijin is very protective of his younger sister. When he discovered that she was being abused and bullied, Ijin thrashed the bullies and utterly destroyed the reputation of the main culprits by anonymously leaking footage to the media. Ijin is very protective about his sister and cherishes her as a proper elder brother.


Ijin's grandfather was devastated after learning of the plane crash, and mourned the deaths of his children. Years later, he was relieved to discover that his grandson Ijin was still alive. He learnt to cook and bought Ijin a smartphone. Ijin is very close to his grandfather.

Lieutenant Kang Hamchan[]

After being rescued by Ijin in the first chapter, Kang helped him retire from the battlefield, treating him as his younger brother. He reunited Ijin with his biological family and trained him to properly adjust to civilian life. Even after leaving his care, Ijin maintains contact with his benefactor. It was Kang Hamchan who heavily classified Ijin's background information, to protect him from suspicion. Interestingly, his fiancee, Shin Jiyeh is Ijin's boss at SW corp.

Kang's military team also saw Ijin like a younger brother and always have his back.

Lt. Kang denied a request to check into Ijin's background from his fiancé, Shin Jiyeh.

Park Yeongchan[]

A nerd whom is Ijin's benchmate in highschool. He was also victim of bullying, until Ijin stepped in and stopped it from happening. Park is also a Challenger in Legends of League (MOBA), whom also plays with Ijin and his friends. Park is the first friend Ijin has made in highschool, he admires Ijin's strength and fearlessness at fighting.

Lee Jaehyung and Ju Hyeokjin[]

Two class bullies who used to harass Park Yeongchan. They give up bullying after witnessing Yu Ijin emerge victorious over Kim Kisoo and his gang. Along with Ijin and Yeongchan, they frequent the internet cafe to play video games. When they were kidnapped by the Gosuk High School Gang, Yeongchan summoned Ijin and Sukjoo to take down the gang and save Jaehyung and Hyeokjin.

Cha Dusik[]

One of the major mafia bosses in Seoul. Cha Dusik was hired by senator Kim Inbae to eliminate Yu Ijin. After being defeated by Ijin, Cha Dusik views him as a worthy opponent. Later, he is surprised when Ijin is able to hack into his system to access incriminating evidence about Kim Inbae's political scandals, and is further surprised when Ijin uses it to secretly destroy the career of the family. Gradually, Cha Dusik and his subordinates become friends with Ijin after the latter saves them from a rival gang.

Koh Sukjoo[]

They started of in rough terms because Sukjoo was very suspicious of him, checking his background and falsified information. Sukjoo assumed he was in some way, after Yuna. But after Yuna gets kidnapped along with Dayun, both Ijin and Sukjoo had no choice but to work together. After that incident the tension died down and they become trusted friends. Sukjoo drops his suspicions, and is impressed by Ijin's superior combat abilities. Later, the two of them work as part time bodyguards at the SW group, although in different teams. With the passage of the series, Ijin and Sukjoo develop a close friendship. Sukjoo is one of the few people Ijin fully trust, and has been a great ally and partner when it comes to face enemies in several times.

Sukjoo admitting that he was impressed and would lose to Ijin

Shin Yuna[]

The heiress of SW group, Shin Yuna attends the same class as Sukjoo and Ijin. Initially, Yuna and Sukjoo were suspicious of Ijin due to his fake background information, but changed their minds after he rescued Yuna and Dayun from kidnappers. Yuna is surprised when Ijin reveals he was acquainted with her deceased father; Shin Ingook. She is moved to tears when Ijin expresses Ingook's dying regret of not spending enough time with his daughter. It is implied that Yuna might have a crush on Ijin.

Shin Jiyeh[]

The director and heiress of the SW group, as well as Yuna's elder cousin. She tried to investigate Yu Ijin after learning of his role in saving Yuna from the kidnappers, although she was shocked that his background was heavily classified by the government. Later, Ijin begins to train with the bodyguards of the SW group. Impressed with his superior abilities, Shin Jiyeh includes him in her personal escort group. Ironically, Shin Jiyeh's fiancee, Lt. Kang Hamchan, was the one responsible for classifying Ijin's information. Shin Jiyeh favours Ijin for his top notch skills as a bodyguard, although she worries about him due to his young age. She is amused to learn that Ijin and her fiance are acquainted with one other, although she doesn't know the exact details about it.

Cha Seoha[]

A young TV celebrity who was being harassed by a stalker. To give Ijin an easy task, Shin Jiyeh assigned him to be Cha Seoha's bodyguard for a while. The actress became comfortable with Ijin and was surprised to learn that he was attending high-school. The next day, Ijin investigated the entire matter- that Cha Seoha's ex-boyfriend, director Ki Donggeun was the culprit, who tried to blackmail her into renewing her contract with his company. After cleaning the mess, Ijin requests Shin Jiyeh to recruit Cha Seoha into her entertainment company, with a better contract. To express her gratitude, Cha Seoha visits Yu Dayun and personally wished her on her birthday.