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Gil Mu Jin is a member of Deung Ha Bul Myung until the completion of its primary mission in reclaiming the throne. Formerly serving as captain of the King's guard during King Jin Hyul's reign, he later presumably serves as captain of the King Jin Jeok's personal guard.


Mu Jin's revealed eyes

Mu Jin is a tall man with brown hair styled in an afro and piercing red eyes that he usually keeps hidden beneath his hair. He also has a scar running through the left portion of his neck. Most of the time, he wears a dirty white jeogori, whose left sleeve he keeps tucked in a dark green arm guard and right sleeve hanging loosely. He sports a red short-sleeved jacket that extends in front and behind his knees, whose right sleeve has dashed-linear design. He then dons a tan joki with brown linings held together by a belt that matches its colour with his arm guard. His light brown baji are also tucked in shin guards, and he wears a pair of white beoseon and jipsin sandals.

During their rebel army operations, Mu Jin's uniform comprises mostly of his regular outfit, albeit with few differences. His jeogori, baji, and long jacket, as well as his arm and shin guards, are all dark brown in colour, with few light brown accents to them. He also sports a red belt where he keeps his sword that has a red hilt. Occasionally, he wears a crimson mask like the rest of his subordinates.

Mu Jin's severed right arm

In his late adolescence, Mu Jin had short shaggy hair parted in the middle where he let his bangs hang loose and wore a forehead band. He wore a jeogori and knee-deep baji tucked into tight arm and shin guards, respectively, and a joki held together by a belt. He also wore a pair of plain hwa. When he became captain of Jin Hyul's personal guard, Mu Jin wore a jeogori tucked into arm guards, over which was a short-sleeved midriff-long vest with an upturned collar. A two-part cloth also hanged in front and behind him that extended to his knees. His baji were folded on his shins, beneath which were bandages alongside a pair of hye. He also sported a belt where he let his sword hang on his left. Later, Mu Jin loses his right arm most likely during the Jeogwa Revolution by Heuk Rang's doing.


In his youth, Mu Jin is shown to have treated others with brotherly warmth, notably with his close comrade Baek Yoo Shin and often trained with him in hopes of honing both their abilities to become more competent fighters and soldiers as they grew up.[1] In his later years, Mu Jin became the captain of Jin Hyul's personal guard, a testament of his skills and loyalty towards the king and the Royal Family. It is assumed, however, that this marked the downward relation between him and Yoo Shin: as the latter sided with the king's consort Yoon Yeon Lee to usurp the throne of Ga Guk, this coup d'état involved having to annihilate Mu Jin's forces. This also resulted to Mu Jin's arm and his fraternal ties with Yoo Shin getting severed.

From then on, Mu Jin has been quite reserved and quiet almost all the time, opting to speak only when necessary. Nonetheless, his loyalty towards Jin Hyul's family, including Yi Jeok and Yi Hwi, remains unchanged, choosing to serve the both of them with allegiance and obedience. As such, he is greatly concerned for both their and his other subordinates' welfare, choosing to protect them as much as he can with his capabilities.


Mu Jin and Yoo Shin in their youth

Mu Jin is a former member of Bi Yeong Ship Mu during King Jin Hyul's reign, where he was a close comrade of Baek Yoo Shin and Baek Ho. Being such, he and Yoo Shin usually trained together and honed their swordsmanship skills, always leaving Mu Jin victorious in the end. Moreover, though it is unknown whether Mu Jin wanted it himself, Yoo Shin occasionally voiced out his vision of becoming Bi Yeong Ship Mu's captain someday.[1]

Later, despite their friendship, Yoo Shin saw Mu Jin as a rival to the point of becoming envious of his achievement, most possibly after Mu Jin became the captain of King Jin Hyul's royal guard.

Sometime after the Hundred Years' War, Jin Hyul ordered for the construction of a secret underground passage in the king's chambers that Mu Jin knew of. Initially, it was a last-resort tunnel to ensure the king's safety from his numerous enemies after Ga Guk's conquest, but the construction of the passage was never completed.[2]

Jeogwa Revolution[]

Main article: Jeogwa Revolution

Mu Jin survives the palace fire

Subsequently, during the Jeogwa Revolution, Yoo Shin succeeded Mu Jin as and finally achieved his dream of becoming captain of the King's guard, the newly-formed Bi Yeong Pal Mu. Yoo Shin believed from then on that Mu Jin died in the palace fire that was caused by Yoo Ja Gyeom.[3] Unknown to him, Mu Jin survived the fire and escaped the palace that night. It can also be hinted this was when he lost his right arm.

Some time after the coup d'état, Mu Jin sided with Crown Prince Yi Jeok and Yi Hwi, who were safely hidden by Wol Young Hwa of Yu Hyang Ru as per Left Minister Seo In Seon Woo's intervention. Mu Jin managed to gather intel from other parties, being able to know about the deaths of Minister Yi Ha and his wife; he later informed the group about this, even to their foster son.

From then on, Seon Woo and Young Hwa devised a plan to keep the crown prince safe from Yoon Yeon Lee, which was ultimately to make Hwi the crown prince's decoy until they reclaim the throne. Amidst initial protests from Jeok, Hwi accepts this task willingly. As Hwi took the title of crown prince, Mu Jin and Baek Ho were assigned to serve him with loyalty, Young Hwa and her daughter Seol Hwa were to keep the secret, and Jeok was to serve Hwi as his liege.[4]

The Deung Ha Bul Myung rebel army was founded later on, establishing their headquarters in Bi Hwa Rim near the palace itself. At some point, Mu Jin taught Hwi his signature swordsmanship of decimating the skin and the underlying organs beneath normal-looking wounds. The Crimson Moon mastered this skill and utilized it during missions.[5][6]


Fateful Encounter Arc[]

On the night of Ga Guk's festival, Mu Jin escorts Nabi along the streets of Hyang Ju. As the fight ensues between Yi Won and Nam Yang Heon with his subordinates, Mu Jin watches from afar and plans to help Won in fighting them as hinted by Nabi, but he finds no more need as Won was able to beat them up alone.[7]

Compact Heist Arc[]

Mu Jin attends the evening rendezvous with some members of Deung Ha Bul Myung including Nabi, Wol Young Hwa, Yi Jeok, Baek Ho, and Seo In Seon Woo regarding the compact. As Nabi volunteers to go steal the compact, he tries to refute along with Baek Ho but agrees thereafter. He is also shocked at Jeok's volunteer and seemingly cannot contest his decision like Nabi. He then ends up being part of the group tasked to find the missing Inspector General along with Baek Ho. In the end, they are unable to find him.[8]

Chase Arc[]

On the night when Yi Hwi, together with Yoo Dan Ah and Won, was chased by the villagers of the slums, Mu Jin strolls with Hwi and Jeok in Bi Hwa Rim. Hwi surprisingly notices Dan Ah wandering around and goes to her, while he and Jeok hide in the trees. As Hwi tends to Dan Ah's injury, he and Jeok leave a pair of plain shoes for Dan Ah's use.[9]

Plague Arc[]

One late night, as Nabi strolls to Yu Hyang Ru from Dan Ah's residence, she is confronted by Jang Rok Ha and is worried that she is unaccompanied. Nabi reassures him that she is in fact accompanied by Mu Jin, who seemingly follows her from the shadows. He then accompanies her back to Yu Hyang Ru.[3]

Mu Jin and Hwi secretly plan to help the plague patients

During the plague outbreak at Moon's End Village, Mu Jin meets with Hwi from a mission in helping the people of the plague-stricken land, giving grain and medicine. He is instructed by Hwi to return to Yu Hyand Ru instantly to sell Nabi's valuables in exchange for money, while he will pursue the fake Crimson Moon. He also orders Mu Jin to keep his individual mission as a secret between the two of them, to which Mu Jin agrees.[10]

After finishing his task, Mu Jin rendezvouses with Hwi at Moon's End Village. He informs Hwi that the medicines were all unavailable, possibly due to the royal court procuring some in case the plague reaches the capital, much to Hwi's dismay.[11] By nighttime, Hwi asks for Mu Jin's help in searching for Dan Ah and Won, who have both gone missing. Under the pouring rain, Mu Jin looks for the two, but to no avail. As he reports this to Hwi, the latter asks him to further scour the entire village to look for them.[12]

Rebel Army Suppression: Setting in Motion[]

Mu Jin continues to plan secretly with Hwi regarding helping the plague patients. During their secret meeting, however, an angry Jeok and Baek Ho infiltrate the room, revealing their secret. Jeok reprimands Hwi once again, but agrees to help him nonetheless for the last time, planning for a midnight infiltration at the palace to retrieve some medicine for the plague patients.[13]

Rebel Army Suppression: Execution[]

As Mu Jin and his team arrive at the palace, they later find out that the medicine is gone. At that point, they also find that Bi Hwa Rim is under fire.[14] As Hwi rushes to Yu Hyang Ru, they immediately secure an escape route for the remaining survivors at the gisaeng house.[15]

Bridal Selection Arc[]

Mu Jin rushes to Jeok and tells him about Hwi's letter

At the rebel army's interim headquarters few days after the attacks, Mu Jin rushes to Jeok and tells him and Baek Ho that Hwi has left a letter behind. As Jeok reads the letter, he rushes to find Hwi, while Mu Jin and Baek Ho follow him cluelessly. In reality, Hwi has decided to pose as Nabi, now Dan Ah's maidservant, in order to enter the palace for the bridal selection. They come across the palanquin near the palace entrance where they spot Nabi in the procession as Dan Ah's companion. Jeok immediately orders Mu Jin to find a way to get into the palace and Baek Ho to look for that person.[16]

Minister Retrieval Arc[]

Baek Ho and Mu Jin sneak in the palace

To help Nabi and Jeok search for Seon Woo, Rok Ha sneaks Mu Jin and Baek Ho in the palace as a cargo from Seo Seo. By midnight, the two slash out their compartment and meet up with the Crimson Moon.[17]

Mu Jin searches for Seon Woo in the eastern wing of the palace, but to no avail. Baek Ho remarks how they had hidden him without a trace, giving the Crimson Moon a sudden thought that he may be hidden in the heart of the palace where he could be guarded with utmost safety and secrecy. Later, as the Crimson Moon locates Seon Woo in the king's chambers, Jin Won himself and his Bi Yeong Pal Mu guards corner him.

Mu Jin meets his former comrade

Mu Jin and Baek Ho later arrive as backup and thwart a handful of soldiers. Mu Jin reunites with his former comrade, Heuk Rang, who mocks his arm's crippled state and asserts that he shall not let them escape. As Jin Won orders Heuk Rang to take on the rebels, Mu Jin releases a smoke bomb, allowing them to escape in a secret underground passage.

As they flee from the soldiers, Mu Jin explains the origins of the secret tunnel ordered upon by King Jin Hyul, but he also informs them of two problems in their escape route: one, Heuk Rang knows of the secret tunnel, and second, the passage has no exit due to its incomplete construction.[2] While waiting for Mu Jin to access a switch for the canal to flood the tunnel, the Crimson Moon deflects the arrows being fired at them by Heuk Rang and his men. At that point, Mu Jin punctures through the wall that forces water from the canal above to flush out the soldiers. They swim through the canal and escape the tunnel.

However, they are immediately found by the guards after turning lights are turned on. Mu Jin, the Crimson Moon, and Baek Ho each carry a dummy of Seon Woo to confuse the rebels. The Crimson Moon reiterates their escape plan to lose the soldiers and meet at the North Gate strictly by five o'clock in the morning regardless whether all three have returned or not. As he wishes them all for their successful escape, the three split up.[18]

Mu Jin and Baek Ho are able to reach the North Gate on time. Though their plan was to leave by five o'clock, the two alongside Jeok and Rok Ha wait for Hwi at the rendezvous point until seven in the morning. Rok Ha asks Jeok what to do, since Gyeom shall leave the palace soon and Hwi seems to have been unable to escape on time. With a blank expression, Jeok entrusts the matter to Rok Ha in the end.[19]

Persecution Arc[]

Sometime later, Mu Jin, Jeok, and Baek Ho are informed that Nabi has surrendered herself as the one who murdered the baby prince. Though Baek Ho worries that they might have to delay or change their plans for the revolt, Jeok instructs them that everything must proceed as planned, more so if it is Hwi's order.[20]

Crimson Moon Rebellion[]

Mu Jin spots the signal

As the rebel army's revolt commences, Mu Jin and the rest of the elite troops wait for the signal behind the North Gate of palace. Later, Mu Jin sights twin pillars of fire emanating from the east and west sides of the palace caused by simultaneous explosives. He then commands his fellow elite troops to charge at the palace as stipulated in their strategy.[21]

Due to their tidal wave-like approach of storming the palace, Mu Jin and his men successfully infiltrate the palace. As they fend off the palace guards, Mu Jin rescues Jeok at some point, killing a soldier about to attack Jeok from behind. At that point, they are notified by one of their cohorts that they have finally located Ja Gyeom.[22]

Mu Jin faces Ja Gyeom before killing the ex-councilor

Mu Jin and some rebels accompany Jeok to the ex-councilor's prison cell, who muses how he was very close to his victory. Ja Gyeom notices Mu Jin, alive and well, after he thought that the former Bi Yeong Ship Mu captain had died in the trap he set for them ten years ago. Ja Gyeom warns Jeok not to get too complacent especially within ten years' time, similar to how they have not predicted events a decade ago. Per Jeok's order, Mu Jin kills Ja Gyeom.

As the latter lays dead, Jeok notices Dan Ah nearby, who has witnessed her father's death. She rushes out of the prison; Jeok stops his cohorts from capturing Ja Gyeom's daughter, believing that children should not be punished for their parents' sins. Afterwards, they head out of the prison.

Mu Jin attacks Heuk Rang

Mu Jin and his men soon arrive at the Queen Mother's quarters before Bi Yeong Pal Mu forces do. Later, Heuk Rang faces Mu Jin and battles him in a death battle. With a single arm, Heuk Rang challenges him how he can fight him, but Mu Jin employs crafty methods to gain the upper hand against Heuk Rang, such as sticking his sword on the ground and uses it as a stand to plunge himself in kicking his opponent. Moreover, Mu Jin remains skillful with his swordsmanship despite his disability. As the latter asserts to Mu Jin that he is now captain of Bi Yeong Pal Mu and that he shall not lose to him a second time, Mu Jin prepares to attack his former comrade.[23] In the end, Mu Jin gains the upper hand and severs Heuk Rang's right arm, later leading to the captain's defeat and death.[1]

Sometime after their successful revolt, Jeok ascends to the throne as King Jin Jeok, the 14th King of Ga Guk. During his inauguration, Jeok asks Mu Jin — presumed to be appointed as captain of the king's guard — where Hwi is, but he also does not know where he had gone off to.[24]

Skills and Abilities[]

As part of the rebel army's elite troops, Mu Jin utilized his knowledge and experience as an ex-royal guard to train other rebel army soldiers. In so doing, at some point, Mu Jin taught Hwi his signature swordsmanship of decimating the skin and the underlying organs beneath normal-looking wounds.[5] He is also highly competent, enough to be one of the most utilised during pursuit and infiltration missions. Moreover, Mu Jin is quite proficient in using the sword, able to fend off attackers and opponents even without his dominant right arm.


  • Mu Jin severs Heuk Rang's arm during their death battle, a parallel to how he lost his own arm possibly by Yoo Shin's own doing.
    • Incidentally, the events when these occurred deposed their erstwhile allegiances: Mu Jin lost his arm during the Jeogwa Revolution that deposed Crown Prince Yi Jeok from the palace, while Heuk Rang lost his arm during the Crimson Moon Rebellion that deposed King Jin Won from his throne. Moreover, these allegiances ascended to the throne as kings during respective events.


  1. 1.0 1.1 1.2 Twelve Nights webtoon, chapter 82
  2. 2.0 2.1 Twelve Nights webtoon, chapter 55
  3. 3.0 3.1 Twelve Nights webtoon, chapter 31
  4. Twelve Nights webtoon, chapter 89
  5. 5.0 5.1 Twelve Nights webtoon, chapter 24
  6. Twelve Nights webtoon, chapter 31
  7. Twelve Nights webtoon, chapter 1
  8. Twelve Nights webtoon, chapter 8
  9. Twelve Nights webtoon, chapter 17
  10. Twelve Nights webtoon, chapter 32
  11. Twelve Nights webtoon, chapter 35
  12. Twelve Nights webtoon, chapter 36
  13. Twelve Nights webtoon, chapter 39
  14. Twelve Nights webtoon, chapter 43
  15. Twelve Nights webtoon, chapter 44
  16. Twelve Nights webtoon, part two final chapter
  17. Twelve Nights webtoon, chapter 54
  18. Twelve Nights webtoon, chapter 56
  19. Twelve Nights webtoon, chapter 57
  20. Twelve Nights webtoon, chapter 69
  21. Twelve Nights webtoon, chapter 79
  22. Twelve Nights webtoon, chapter 80
  23. Twelve Nights webtoon, chapter 81
  24. Twelve Nights webtoon, chapter 86


Characters of Twelve Nights
Ga Guk
Royal Family Ahn YoungHyun BinJin HyulJin JeokJin WonUnnamed Baby PrinceUnnamed Baby PrincessYi HwiYi Sae GiYoon Yeon Lee
Ministers Hwang Se HyungKim Hak GyuSa Hwa HyeonSeo In Seon WooWi Ji HyunYi HaYoo Ja Gyeom
Bi Yeong Pal Mu Baek AhBaek JuBaek LinBaek RyungBaek SaHeuk Rang
Bi Yeong Ship Mu Baek HoBaek Yoo ShinGil Mu JinYi Ha
Deung Ha Bul Myung Baek HoCrimson MoonGil Mu JinNabiSeol HwaSeo In Seon WooWol Young HwaYi HwiYi Jeok
Yu Hyang Ru NabiWol Young HwaYi Jeok
Others ChungHwang Se RyeonHyunMa Mi SongNam Yang HeonSoriWoonYi Ha's WifeYoo Dan AhYoo Dan Ah's Mother
Seo Seo
Royal Family First PrinceFirst PrincessJang ReiJang Rok HaJang RyunSecond PrincessThree Wives of Jang RyunUnnamed Baby PrinceUnnamed Baby PrincessYeong Bi
Others Gwak Ji RyeonMeng Gyeom