Kang Sae-byeok/Synopsis

The story of Kang Sae-byeok from Squid Game.
==Background==
Kang Sae-byeok was born in North Hamgyong Province, North Korea. When Sae-byeok was still a child, there was a plague going through her town which killed her grandparents and her older brother. She saw soldiers carrying their corpses to a pile and lit it on fire, burning them together.
Eventually, Sae-byeok and her family decided to leave North Korea to start a better life in the South. While trying to swim across the border, Sae-byeok's father was shot and drowned. Her mother hid in China, but then was sent back to North Korea once the immigration agents found her. In the end, only Sae-byeok and her younger brother, Kang Cheol, managed to enter South Korea. 
While living in South Korea, at some point, Sae-byeok worked with the gangster Jang Deok-su in order to survive. Deok-su gave her food and shelter, besides teaching her his skills. However, the relationship with the traitorous gangster took more from Sae-byeok than it gave her. Sae-byeok later decided to cut ties with Deok-su and become independent, so she backstabbed him and left.
In 2020, Sae-byeok is a young woman in South Korea, struggling to scratch a living as a pickpocket while her 10-year-old brother is in an orphanage. Sae-byeok uses the money she stole to pay a broker in attempt to find and get her mother out of North Korea. Sae-byeok's wish is to gather enough money to buy a house, get her mother out of the North and her brother out of the orphanage, then reunite her family in a new home. Needing the money to help her family, Sae-byeok accepted the offer to participate the 33rd Squid Game, a mysterious competition with a large sum of money as a prize. 
==Squid Game==
==="Red Light, Green Light"===
Sae-byeok is first seen in a betting shop, where Seong Gi-hun accidentally bumps into her while he is being chased by a group of loan sharks that he owns money to. As he apologizes for knocking her down, she pickpockets the money he won gambling on a horse race. 
At some point, Sae-byeok accepted to join the Squid Game. After the 456 players were put to sleep and taken to the island where the games happen, she is designated the number "067" and the masked workers dressed her in her player uniform. Waking up inside the dormitory, Sae-byeok reencounters the gangster Jang Deok-su. The gangster starts to beat her in front of everyone, causing a crowd to gather around them. Deok-su says he wasn't expecting to find her here. Sae-byeok stands defiant before him, so Deok-su notes that her temper hasn't changed but she never was the type to wuss out because of a couple of blows. He accuses her of betraying him after he gave her food and a home, and even taught her his skills, only for her to backstab him and then leave. Sae-byeok argues that he took more than she owes him. Deok-su wonders why she would run away then. Sae-byeok replies she didn't run away, she became independent. Deok-su laughs then repeatedly beats her while trying to humiliated her in front of the others because she is from North Korea. 
Deok-su's attack is interrupted when Gi-hun recognizes Sae-byeok and gets between them, shoving Deok-su away from her. Gi-hun grabs Sae-byeok and sees the scar she has on her neck, confirming that it is the same girl who stole from him. Gi-hun shakes Sae-byeok and demands his money back, but is kicked away by Deok-su. The gangster confronts Gi-hun because of this interruption, saying he is still not done with Sae-byeok. They stop, however, as the masked men of the Squid Game arrive to welcome them and explain the rules of the competition. Sae-byeok is seen listening the staff tell the players the rules and then signing the consent form with the three clauses of the game. 
The first game happens in a room constructed to resemble a field and is revealed to be Red Light, Green Light. The players have 5 minutes to cross the finish line without being caught by a giant motion sensor doll. During the game, Sae-byeok and the other players discover that the losers of a game are killed, as they realize that the participants whose movements are caught by the giant doll are immediately shot by guns placed in many small openings on the high walls of the location. Sae-byeok figures out she can hide behind other players to survive the first game without being detected by the doll. She hides behind Deok-su, using him as her shield, and the gangster soon realizes that someone is behind him. While standing frozen during red light, the gangster questions who it is. Deok-su becomes angry upon hearing Sae-byeok replying. She grabs his hair from behind and threats to push him, which terrifies the gangster. He trembles and begs her not to do it. Sae-byeok laughs at his cowardice and reminds him that he will be dead if the doll detects him trembling. During the next green light, Sae-byeok pulls Deok-su by the hair, making him fall backwards on the ground. Sae-byeok runs past the fallen Deok-su and stops nearby as the doll quickly says "red light" again.
Her strategy works well and she crosses the finish line with more than 20 seconds before the time is over, being closely followed by Deok-su.
==="Hell"===
During the first game, 255 players were eliminated, so 201 remain in the competition. After witnessing more than half of them being killed, most of the remaining players are scared and beg the masked staff to let them go. Cho Sang-woo reminds the masked manager about the third clause of the consent form, which says that the players can vote and the games will be terminated if the majority agrees. However, before the vote, the manager announces that 25.5 billion of prize money was accumulated from the first game and they also reveal that the final prize will be ₩45.6 billion. But if they quit the games, all the money will go to the families of the deceased players, and living players will be left with nothing. Sae-byeok is impressed by the great amount of prize money accumulated inside the piggy bank from the first challenge. This makes her decide to vote for the games to continue. However, the majority votes to stop the games, which disappoints Sae-byeok. Because of this result, the staff announces that the games are terminated, unless the majority later decides to play again.
Out of the games, the staff drops Sae-byeok with Gi-hun on the street at night. They are both tied, blindfolded and only wearing their underclothes. Gi-hun screams for help, not knowing that Sae-byeok is with him. Sae-byeok tells him to shut up and takes off his blindfold. Once Gi-hun recognizes her, she asks for his help to be untied. Gi-hun bites the ties which are holding Sae-byeok's hands, allowing her remove her blindfold, untie her feet and stand up. While she is dressing her clothes, Gi-hun asks for her help to be untied. He tells her to hurry because the night is cold and he is freezing. But after getting dressed, Sae-byeok starts to walk away. Gi-hun calls for her, reminding her to untie him before leaving. Sae-byeok turns and asks him why she would do it, so Gi-hun replies that she should help him because he untied her. Sae-byeok asks if Gi-hun is stupid or just naive to think such thing at his age. She refuses, saying that Gi-hun will just demand the money she stole again. Gi-hun says he will forgive her about the money, but Sae-byeok still doubts it, so he swears on his mother's life that he will. However, when Sae-byeok cuts the ties around his hands with her switchblade, he does exactly what she expected. She laughs at him clumsy jumping trying to get her with his tied feet and telling her to give back his money. She feels bad for his mother, as Gi-hun would swear on her in vain. Sae-byeok then leaves him still tied and undressed on the street.
She is later seen visiting her younger brother, Kang Cheol, in the orphanage. Sae-byeok offers Cheol ice cream and notices that something is wrong when he doesn't take it. She sees that her little brother's face is hurt and asks if he fought with his friends, but Cheol doesn't reply. As Cheol is clearly upset, Sae-byeok says that she will leave if he keeps silent. Cheol then starts to cry, saying he doesn't want to stay in the orphanage. Cheol reminds Sae-byeok that she promised to bring their mother from North Korea and they would be living all together after a month. He adds that the other kids told him that his sister is lying and he will never leave the orphanage, because Sae-byeok abandoned him. Sae-byeok embraces her brother and assures him that this is not true. She tells him that their family will be living together in the same house by the next year. Sae-byeok wipes her little brother's tears and reminds him that she always keeps her promises, before hugging him again.
Afterwards, Sae-byeok visits a North Korean broker employer, who talks about the broker she paid to take her mother out of Korea. The man says that the broker took her money and fled, and she is not the only victim of a case like this. Because he claims it is very hard to track down a broker once they fled, he says that she will need to hire a new broker and star over. The employer tells her she will have to pay ₩40 million to start again, but Sae-byeok doubts the man. She throws his hot coffee at him and threats him with her switchblade, saying she believed him the last time and risked her life for the money which was lost. She says she will bring the money, but adds that if he tricks her again, she will cut open his throat. Right after Sae-byeok left, the man looks the pocket inside his jacket and realizes that the girl had stolen his money while she was threatening him.
Sae-byeok later has another chance to rejoin the games when the majority decides to return. At night on June 23, Sae-byeok waits for the Squid Game staff to take her away to the games again. At 12 p.m. sharp, a passenger van being driven by a masked worker appears. Sae-byeok gets in the van, however, when the masked staff tries to use sleeping gas on her, she is prepared. Instead of being put to sleep like the other players, Sae-byeok holds her breath and is taken to the island while still awake.
==="The Man with the Umbrella"===
Being awake when she was taken allows her to smuggle her switchblade to use in the games. When the masked workers are taking off her clothes of the unconscious players to dress them in their Squid Game uniforms, she uses her pickpocket skills to hide the blade inside the pocket of one of them. Then, once she is dressed in the uniform, she recovers the blade from the worker's pocket and hides it under her sleeve without any of the masked men noticing. 
Back in the games with other 186 players, Sae-byeok reunites with Deok-su again. He offers an alliance, saying he will forget all that happened between them in past and asks her to join the gang he is forming for the next games, reminding her that they once worked well together. Not trusting Deok-su, Sae-byeok recalls that others gangsters are hunting him down outside the games because of how traitorous he is. Deok-su tells Sae-byeok that even though she's tough, she won't survive playing alone. Sae-byeok responds that he should worry about himself. She tells the other members of his group not to ally with Deok-su, revealing that stole from other members of his gang outside the games. She explains that he stole from his own subordinates and later from his boss, which got him in trouble when he was caught and led him to join the Squid Game to pay his debts. She finishes saying that he is a revolutionary asshole, which infuriates Deok-su and he moves to attack her, making her discreetly draw her hidden blade. They are interrupted by Han Mi-nyeo, who approaches Deok-su and asks to join his group.
Noticing the vents on the ceiling of the game facility gives Sae-byeok an idea of how to try to discover something about the next game. After the curfew, Mi-nyeo makes a fuss, demanding that the guards outside the players' dormitory let her go to the bathroom. When a masked soldier finally decides to accompany Mi-nyeo to the bathroom, Sae-byeok takes this opportunity to execute her idea. She approaches Mi-nyeo and the soldier, saying she needs to go too. Mi-nyeo is annoyed to see that Sae-byeok is taking advantage of her effort after his scandal to be allowed to go. Sae-byeok ignores her, making Mi-nyeo call her rude.
In the bathroom, Sae-byeok startles Mi-nyeo when she opens the door of her stall holding her blade. Mi-nyeo had smuggled her cigarettes and lighter to use in the games and actually came to the bathroom to smoke in secret from the staff, so she offers Sae-byeok a cigarette. Ignoring the offer, Sae-byeok uses the blade to unscrew the cover of a vent on the ceiling and reveals to Mi-nyeo that she is going inside it to investigate. She asks Mi-nyeo to distract the guards and promises to tell her if she finds out something. Mi-nyeo agrees and helps Sae-byeok get into the vent by letting the girl step on her shoulder. 
Crawling inside the vent, Sae-byeok follows a smell which leads her to the kitchen, where she sees the workers bellow her melting something in large pots. She is briefly startled when a rat climbs onto her shoulder, causing a worker to look up upon hearing a noise coming from the vent. Despite this, Sae-byeok manages to go unnoticed and returns to the bathroom in time to help Mi-nyeo with her act to distract the guards. When the soldier waiting for them decides that the two women are taking too long, he goes inside the bathroom and opens the door of their stall, but finds Mi-nyeo with her pants down and Sae-byeok beside her, pretending to help with her constipation. As Mi-nyeo accuses the soldier of sexual harrassment for not respecting her privacity and then leaves, Sae-byeok follows her. As they return to the dormitory, Mi-nyeo asks Sae-byeok what she saw. Sae-byeok replies she will tell her in the next day. 
In the morning, Mi-nyeo asks Sae-byeok again, reminding the girl that she said she would tell her. Sae-byeok hesitantly tells her about the workers melting something in pots. Mi-nyeo wonders what it was, but Sae-byeok replies that she isn't sure. Mi-nyeo becomes annoyed because after all her efforts to distract the soldier, this is all that Sae-byeok discovered. Sae-byeok then adds that it smelt like sugar. Mi-nyeo is still not completely satisfied with Sae-byeok's answer. Mi-nyeo threats to burn the girl's eyes with a cigarette in case she is hiding something. In response, Sae-byeok just shoots her a long look, causing Mi-nyeo to let it go. She claims to be hungry and leaves for breakfast, saying she wants to eat something sweet.
Sae-byeok receives a wrapped bun from the masked workers but stares at it instead of eating it. Unknown to her, she is being watched from afar by Sang-woo. When the players are going up the spiral staircases while walking to the location of the next game, Sang-woo approaches Sae-byeok and asks her what she saw last night. He reveals that he overheard she talking with Mi-nyeo when they were walking into the dormitory. Sae-byeok sees no reason to tell him anything, so Sang-woo explains that the games in the competition are the ones he played when he was a child. He says that if she tells him what she saw, he might guess the next game easier than her, who is a foreigner and is not familiar with these games. This convinces Sae-byeok, and she tells him about the workers melting sugar.
The location of the second game is a playground. The announcer says that the players should choose one of the four shapes on the doors before the game and stand in front of it. Keeping in mind what Sang-woo said about being able to guess the game, she watches him from afar. When Sang-woo chooses the triangle, she follows him, picking the same shape. The game is revealed to be Dalgona (Sugar Honeycombs) and players have 10 minutes to cut out their shapes without breaking or cracking it. Sae-byeok's hunch that Sang-woo indeed guessed the game is proven to be correct, as he chose the easiest shape to cut out from the honeycomb.
As result of following Sang-woo and picking the triangle shape, Sae-byeok is one of the first players to complete the challenge within the time limit. She cuts out the shape of her dalgona candy and finishes it just over 5 minutes after the start of the game. She shows her triangle to a soldier and leaves the playground, even before Sang-woo finishes cutting out his own candy. Sae-byeok is later seen going down the spiral staircases while going back to the dormitory, along with other players who survived this game.
==="Stick to the Team"===
After the players returned to the dormitory from the second game, the announcer says that 79 players were eliminated in this round, and Sae-byeok watches impressed as more ₩7.9 billion is added to the piggy bank. With this, 108 players remain in the games.
During lunch time, the workers serve each player only hard-boiled egg and a glass bottled soda. A few players get no food to eat after Deok-su and his gang got in line twice. Because of this, Player 271 confronts the gangster, and Sae-byeok and the others witness Deok-su beat him to death. Sae-byeok and the other players witness Gi-hun begging the masked staff to do something about Deok-su murdering 271. The staff, however, ignores Gi-hun. 271 is simply added to the eliminated players, more money is added to the piggy bank and two masked men arrive with a coffin to take away the body. Because there is no punishment for this murder, they all realize that players can kill each other in between games. 
Afterwards, 30 minutes before the lights out, Sae-byeok is sitting by herself and Gi-hun notices Deok-su and Player 278 watching her. Thinking Deok-su's gang is planning to attack her after the lights out, Gi-hun goes to Sae-byeok and asks if she will be okay because he knows that she is not on good terms with the gangster. Gi-hun invites her to join his team, which will be reunited by his bed, in case something happens during the night. However, Sae-byeok says that she doesn't trust anyone, especially the players of the Squid Game. Gi-hun is surprised by her response and tells her that they don't trust people because they are trustworthy, but because they have no other choice. Sae-byeok then watches Gi-hun walk away, leaving her alone again. When the lights go out, Sae-byeok is seen lying awake on her bed, preparing for what will happen next.
After the lights go out, a riot led by Deok-su and his gang ensues. As the lights start to flicker on and off, Sae-byeok draws her blade to protect herself, but then she is attacked by Deok-su and a member of his gang, Player 040, who attempts to strangle her with a bed sheet. She fights them off and manages to cut Deok-su with her blade, wounding him on the leg. When the gangster holds her against a wall and tries to strangle her, she kicks his lower parts and escapes, although this results in her dropping her blade which is caught by Deok-su. The gangster immediately goes after her and blocks her way, but Player 331 jumps down from the top of a bunk and tackles him, giving Sae-byeok enough time to flee.
Sae-byeok runs and seeks Gi-hun and his team for protection. She reunites with Gi-hun, who becomes surprised to see her. She reminds him that he asked her to come, and they soon realize that she was followed by Deok-su. The gangster tries to stab Sae-byeok with her own blade, but Gi-hun shoves her and pushes Deok-su away. Sae-byeok fights Deok-su's gang along with Gi-hun, Sang-woo and Ali Abdul. When Deok-su sweeps the blade trying to stab Gi-hun, Sae-byeok defends Gi-hun by kicking the gangster. However, she is attacked from behind by Player 303, who breaks a glass bottle on her head, knocking her down. Sae-byeok is defended by Sang-woo, who attacks 303 using a metal bar while Gi-hun helps her to stand up again. The two teams face each other in a standoff. Because Sae-byeok is being defended by Gi-hun and Sang-woo's team, Deok-su tells Gi-hun that less players alive would benefit him too. Gi-hun responds that Sae-byeok is one of his team. Then, they all spot the elder Oh Il-nam pleading the players to stop killing each other from the top of a high bunk, right before the masked staff enters the dormitory to end the riot. While patting down the players' clothes for weapons, a soldier finds Sae-byeok's switchblade inside Deok-su's pocket and confiscates it.
During the riot, 27 were killed, so now 80 players remain in the games. Right after, Sae-byeok sits with Gi-hun and the others of their team. Sae-byeok sits behind the group and hears in silence while they talk. Gi-hun reminds the members of the team that they still don't know each other's names and says they should introduce themselves. After Gi-hun, Ali and Sang-woo said their names, Sang-woo and Gi-hun turn to Sae-byeok. Gi-hun nods asking her to say her name. Sae-byeok hesitates, unsure if this is necessary. Gi-hun tells her that they are on the same side now and need at least to know each others' names to build the trust among their team. Sae-byeok reveals her name, and Gi-hun says it is a pretty name but it doesn't suit her. Lastly, Ali asks for Il-nam's name, but the old man stutters, causing Sae-byeok and the others to stare at him in confusion. Il-nam seems unable to remember his own name, so he is the only one who doesn't reveal it.
In the following morning, when the lights come up, Sae-byeok and her teammates wake up and Il-nam is sitting next to them awake, having stayed up all night. Il-nam explains he was afraid there would be another attack and because he wasn't much help during the riot, stand guard is the least he can do for the team. Following this, they all hear the announcer say that the next game will begin soon. Later, they enter a white room as the announcer says that the third game will be played as a team and players have 10 minutes to form teams of 10. Sae-byeok hears as Sang-woo and Gi-hun talk about the new teammates they should invite to join their team. Sang-woo concludes that they should bring men to the team because they already have an elder and a woman, and adds that they should split to look for new members. While searching for someone to join the team, Sae-byeok sees Ji-yeong sitting by herself. Sae-byeok approaches Ji-yeong and asks the girl to come with her.
Reunited with the group again around 1 minute before the time is over, Ji-yeong joins the team along with Player 276, Player 196 and Player 244. Sang-woo asks Ji-yeong who brought her to the team and she points to Sae-byeok. Sang-woo reproves Sae-byeok's choice, reminding her that he asked for men to improve the odds of their team. Ji-yeong feels unwelcomed and tries to leave but Gi-hun stops her because they are out of time to search for someone else. Right after, Mi-nyeo, who was betrayed and abandoned by Deok-su, approaches them. Mi-nyeo says she will join them, then looks at Sae-byeok and Ji-yeong before stating she will be more useful to the team than two scrawny girls. The whole team stares at Mi-nyeo but they reluctantly accept her as they are out of time to look for teammates.
Moving to the location of the third game, they enter a space where there are two huge towers with platforms forming a bridge-like structure but with the middle missing. The game is revealed to be Tug-of-War and players should pull the rope towards their platform to make their opponents fall to their deaths. When their team is sorted to go against team 5, a group with only men, the group becomes discouraged. However, Il-nam proposes a strategy to win that will allow them to win with teamwork, even with a weaker team. Arriving on the platform, both teams play Tug-of-War after being shackled by the workers to the rope. Sae-byeok and her teammates execute Il-nam's strategy and it temporarily works well, but the other team eventually manages to pull back the rope, causing them to be dragged very close to the edge. As they are about to fall to their deaths, Sang-woo comes up with another plan, telling his teammates to move three steps forward to knock down the opposite team.
==="A Fair World"===
Sang-woo's plan allows them to knock down the other team, pull back the rope and win the game. After the Tug-of-War, the entire team is exhausted. While they are in the elevator on their way out of the place, Ji-yeong gets annoyed with Player 244, who is a pastor and keeps praying to God instead of thanking Il-nam and Sang-woo for being alive. The two of them start an argument, making Sae-byeok irritated. She tells them both to shut up. Outside the elevator, as they walk out of the location, Ji-yeong asks Sae-byeok for her name. Sae-byeok why she wants to know and Ji-yeong replies she wants to call her by her name. Sae-byeok sees no need to tell Ji-yeong her name and refuses to reveal it, making Ji-yeong say that Sae-byeok is too reserved. Sae-byeok tells Ji-yeong to leave her alone. Ji-yeong reminds Sae-byeok that she was the one who spoke with her first. In third game, 40 people were eliminated and now 40 players remain in the games.
Later, the whole team sits together while eating corn for dinner. With 30 minutes left before the lights go out, Sang-woo recalls the riot in the previous night and tells the team that they should prepare in case it happens again. While the team plans what they should do, Sae-byeok tells them that during the riot she saw a man die in front of her, with his neck being broken by his own ally. She questions the team if they trust her and reveals the group that she doesn't trust any of them. Gi-hun tells the team that they should set up a barricade, so Sae-byeok is seen helping Ji-yeong as their group moves the metal parts of their beds. 1 minute before the lights go out, the whole team is reunited inside the barricade. Sang-woo and Gi-hun then suggest Sae-byeok and the others that they should take turns sleeping and keep a watch in pairs to protect the members of their team during the night. 
During Gi-hun's guard duty with Il-nam, the elder seems to become ill. Gi-hun tries to wet a cloth to place on Il-nam's forehead and break the old man's fever, but realizes the bottle is empty. Sae-byeok, who had woken up, offers Gi-hun her water bottle so he can help the old man. After Gi-hun put Il-nam to sleep, he tells her that Sae-byeok should go back to sleep because he can watch by himself. However, she reminds him that they planned to keep the guard in pairs and she is already awake anyway. Gi-hun thanks her for the water bottle. Sae-byeok says that it wasn't for free and he should pay her back in the next day, making Gi-hun grin upon hearing this.
Later, Sae-byeok is sleeping on her bed when all players are awakened by the lights snapping up and the sound of a siren. As she and her teammates get out of their beds, they see the masked staff entering the dormitory to check on them.
==="Gganbu"===
After being awakened, all teams stand in lines while being checked by the staff. Then, the announcer says that the fourth game will begin soon. Going up the spiral staircases, Sae-byeok and the other players are surprised at the sight of five corpses hanging from their wrists on a giant mobile: Player 111, two soldiers, a manager and a worker. A manager explains that this is the fate of the people who broke the rules of the games for their own benefit and tainted the ideology of equality of the competition.
Entering the white room again, the announcer says that players have 10 minutes to form pairs for the next game. Once two people agree to play together, they should shake hands to become partners. Right after, Sae-byeok and her teammates are gathered. When Mi-nyeo asks Gi-hun and then Sang-woo to be her partner, but is rejected by both, Sae-byeok tells her not to humiliate herself because she will not convince anyone to play with her like this. She then looks at Gi-hun and Sang-woo, then says they should just be honest and admit no one wants risk themselves playing with a woman or with the old man. As Sae-byeok stands up and is about to go to look for a partner, Gi-hun asks where she is going. Sae-byeok stops and turns to him, then asks him why he is interested and if he wants to play with her. Because Gi-hun doesn't reply, she just leaves. Sae-byeok is followed by Ji-yeong. 
Less than 4 minutes before the time is over, Sae-byeok is looking around and searching for someone to be her partner. Ji-yeong approaches and asks Sae-byeok to play with her. Sae-byeok is uncertain of this and Ji-yeong asks if she willing to humiliate herself by asking the others. Sae-byeok replies she doesn't care with humiliation because she needs to win. Ji-yeong assures that she will make sure Sae-byeok wins if they play together and will do whatever it takes for it to happen. Upon being asked about the reason she invited Ji-yeong to join her team before the Tug-of-War, Sae-byeok reveals that she did it because Ji-yeong was the only person who looked like she would accept. Ji-yeong says she feels the same, and this is why she is asking Sae-byeok now. Ji-yeong extends her hand and Sae-byeok holds it, accepts Ji-yeong as her partner. The two girls sit together in the white room until the time to choose partners is over, then they walk together to the place of the next game.
The location of the fourth game is a room constructed to resemble a neighborhood with small houses and alleys. The players gather next to the entrance and are asked to follow the soldiers who will guide each duo to their positions in the place. After walking through an alley and following the soldier who is leading them, Sae-byeok and Ji-yeong arrive at their position and their soldier escort gives each a pouch with 10 marbles. Thus, they find out they will be playing Marbles. However, the announcer reveals that the partners will have to play against each other instead of together. The one wins all the marbles of the partner in 30 minutes will pass this game. This revealation surprises both girls. Although Ji-yeong is still calm and turns to look at her partner, who looks shocked. Ji-yeong thinks this is the biggest one since the Korean War. Sae-byeok immediately asks what they will play, causing Ji-yeong to say that she is as cold as ice. Ji-yeong jokingly asks if Sae-byeok is a spy from the North and Sae-byeok tells her to cut it out. She asks Ji-yeong once more to say what game they are going to play. Ji-yeong replies she has no idea because marbles is what boomers used to play as kids. Since the staff said they can create the rules of the game, Ji-yeong says she will think about something to play.
Ji-yeong reflects about it and then suggests they bet everything they have and end the game with a single round. Ji-yeong sees Player 244 and Player 196 throwing their marbles nearby and asks Sae-byeok if she really would like to spend the entire time they have left playing like the two men. Sae-byeok looks at 244 and 196 and agrees she doesn't want to spend their remaining time like them, but still wants to know what they will play. Ji-yeong wonders why Sae-byeok is in such a hurry, and playfully asks if she is so eager to kill her. Ji-yeong explains that it is going to be a single round and there is some time left, so they can play only in the last minutes. Sae-byeok asks what they will do until then. Ji-yeong suggests they spend their time talking about things they never told anyone else. She says they could tell each other anything without fear of embarrassment because one of them will die anyway. 
The two of them bond over their dark backgrounds. Sae-byeok tells Ji-yeong that her family came to the South Korea for a better life. Sae-byeok's little brother, who is now in an orphanage, came with her, while her father died trying to cross the border and her mother was sent back to the North after immigration agents found her hiding in China. Sae-byeok tells that she wants the prize money to buy a house for her family, get her brother out of the orphanage and bring her mother from the North. Ji-yeong says that she could do so much more with the prize money and asks if there is somewhere she would like to go. Sae-byeok replies she would like to visit the Jeju Island because it is exotic and different from Korea. Ji-yeong says that Sae-byeok should think bigger, suggesting her go to Hawaii or at least to the Maldives and drink mojito. Sae-byeok looks at Ji-yeong confused, wondering what a mojito is. Ji-yeong tells her that it is like the movie with Lee Byung-hun, in which he says to "go to mojito and have a glass of Maldives". Sae-byeok shakes her head, telling Ji-yeong she doesn't know about the movie or mojito, making Ji-yeong laugh. Ji-yeong says that she will show her how people splurge in the South and teach more once they are out of the games. Upon hearing this, Sae-byeok sadly looks away. Ji-yeong then pauses as she recalls that they won't be leaving together.
Ji-yeong asks if Sae-byeok had ever seen a dead body before joining the Squid Game. Sae-byeok tells her about the plague in her town that killed her grandparents and older brother, and she saw their bodies being burned together. Upon hearing this story, Ji-yeong says that Sae-byeok's stories are way too dark. Sae-byeok asks her the same question, so Ji-yeong then reveals her own dark past. Ji-yeong says that she found her mother dead one day after coming back from school, and also saw her father holding a knife beside the corpse. Ji-yeong says that her father was a pastor and was very abusive towards her and her mother. She later killed him herself with a knife. Ji-yeong says her father would always pray after molesting her and her mother. But he didn't pray in the day he murdered her mother and Ji-yeong thinks that he knew he would not be forgiven for this action. Ji-yeong was arrested for killing her father and when she was released, someone gave her the Squid Game card and she accepted the offer because she had nowhere to go. Ji-yeong reveals she has no idea where she will go after the games and asks Sae-byeok if she wants to go to Jeju Island with her, only to remember again that they can't leave the Squid Game together.
When they have less than 3 minutes before the game is over, Sae-byeok turns to Ji-yeong and says that they should play. Ji-yeong agrees, so the two girls stand in front of a wall to finally play. They choose a simple game in which the winner will be the one who manages to throw the marble closest to the a wall before them. Before playing, Sae-byeok finally decides to reveal her name. Ji-yeong states that Sae-byeok's name is nice and then also introduces herself. Sae-byeok asks for her family name and Ji-yeong replies she doesn't have one. Deciding who should start the game, Ji-yeong states that Sae-byeok can play first because her player number is lower. After Sae-byeok threw her marble close to the wall, Ji-yeong drops hers on purpose, surprising Sae-byeok. 
Sae-byeok grabs Ji-yeong and pushes her against a wall, asking the girl what she is doing. Ji-yeong simply says she lost, claiming that the marble just slipped from her fingers. Sae-byeok asks if this what Ji-yeong meant with "granting her victory". Irritated, Sae-byeok says she won't be grateful for this and tells Ji-yeong to play again. Ji-yeong admits she would not be able to win anyway and asks to Sae-byeok to let her lose in style. Sae-byeok yells that Ji-yeong should stop acting cool and throw the marble again. Ji-yeong then confesses she has nothing, no reason to leave the Squid Game. Ji-yeong reveals she has been thinking about what she would do once she gets out since Sae-byeok asked her earlier, but no matter how much she tried, she couldn't think of anything. She thinks that someone with a a good reason should be the one to survive because it is the right thing. Ji-yeong believes that Sae-byeok has a good reason to live: to help her family. Ji-yeong asks Sae-byeok to make sure she leaves the games alive, and tells her to meet her mother, recover her brother, and go to Jeju Island. Sae-byeok becomes emotionally distraught and cries as she hears Ji-yeong. 
As Sae-byeok walks away from the location of the game accompanied by a masked soldier, she hears Ji-yeong calling out to her and stops. She hears Ji-yeong's last words, thanking Sae-byeok for playing with her. Right after, the girl is eliminated from the games. Sae-byeok flinches at the sound of a soldier shooting Ji-yeong in the head, which is followed by the sound of her partner's body falling to the ground. After Ji-yeong was killed, Sae-byeok stands a few moments crying, before gathering the strength to move on. Without looking behind her, Sae-byeok leaves the place mourning the loss of her close friend. 
==="VIPs"===
Only 16 players survived the Marbles game. Along with Ji-yeong, 4 other teammates of Sae-byeok were eliminated during the game: Ali, Player 276, Player 196, and Il-nam (but unknown to all players, the old man just left without being killed). Back in the dormitory, players find out that Mi-nyeo, who was left without a partner, was allowed simply to skip the fourth game instead of being eliminated. With this, 17 players remain in the competition.
Later, they all sit on their beds eating after being given a potato and a bottle of water. Sae-byeok is still so heartbroken about Ji-yeong that she can barely eat. She stares at her potato, then she slowly takes tiny bites of it. She and the others witness Player 069 break down in front of everyone because he lost his wife in the fourth game. Player 069 begs the others to vote to terminate the games, but Sae-byeok and the other contestants don't repond to his pleas. Sang-woo stands up and confronts Player 069 about him surviving the Marbles game instead of letting his wife live as well as his weak will to continue. He reminds 069 that many players died in the games besides his wife, and leaving now would mean not only to go back to a miserable life, but also to carry the guilt for all these deaths. Sang-woo turns to the others and challenges them to stand up and leave if they want to live this miserable life outside. None of the players reply, including Sae-byeok, who is still sadly looking down while hearing Sang-woo's speech in silence. 
After the lights go out, Sae-byeok and some other players sit on their beds awake for awhile instead of sleeping right away. In the next morning, Sae-byeok and the others wake up when guards enter the dormitory carrying a coffin and then they become surprised and saddened (except for Deok-su) upon seeing that Player 069 hanged himself with the sheets of a bed during the night. Shaken, but still willing to win, Sae-byeok participates in the fifth game with the 15 remaining contestants. Following the announcer saying that the next game will begin soon, the players go up the spiral staircases while walking to the location of the game. Sae-byeok is seen going up the stairs right behind Gi-hun. Entering the white room before the game, they see mannequis wearing pink vests numbered from 1 to 16. The announcer says that players should choose one of the mannequins and wear its corresponding numbered vest. When the announcer adds that the numbers are the order in which they will be playing the game, Sae-byeok picks number 15, which means she will play right after Sang-woo, who chooses number 14. Before the game begins, Gi-hun chooses number 16, so he plays after her in the sequence. 
Moving to the location of the game, they enter a space constructed to resemble a circus tent, where there is a high bridge with 18 pairs of glass tiles. The game is revealed to be Glass Stepping Stones and the announcer explains that each tile is made of either tempered or normal glass. The tempered glass can withstand two players, but the normal glass will shatter with just one person. Players should guess which tiles are tempered and only step on them to cross the bridge safely. They have 16 minutes get to the other side. Less than 10 minutes before the time is over, Sae-byeok, Gi-hun and Sang-woo are the only ones left on the platform, waiting to move to the glass tiles. Sae-byeok hears Gi-hun saying that the three of them will be able to cross safely if the players in front of them guess one or two tiles correctly, but Sang-woo points out that if the other players become scared and waste time, it can be dangerous for them, who are at the back. Due to the delay of the players in front of her, Sae-byeok is only able to move to the first glass tile less than 8 minutes before the game is over. When Gi-hun tries to follow her, he forgets which of the tiles is normal and which one is tempered glass, so Sae-byeok tells him and asks him to focus. Gi-hun thanks her for helping him.
Less than 3 minutes before the time is up, the majority of players were eliminated for falling into normal glass, and there still 4 tiles to be figured out. Sae-byeok, Gi-hun and Sang-woo follow the last player in front of them, Player 017, a man who formerly worked as a glass worker. They move forward 3 glass tiles being guided by 017 until the overseer of the games, the Front Man, notices the advantage and turns off the lights. The absence of light causes the glass worker no longer be able to visually distinguish which glass is normal and which is tempered, just as they need to figure out only the last tile. 
With less than 1 minute before the time is over, they make one last attempt to figure out which glass is which through the sound, with 017 asking for something to throw on the glass. Sang-woo pats himself down and finds nothing, so he turns to Sae-byeok and Gi-hun, asking if they have anything. Sae-byeok shakes her head, telling Sang-woo she doesn't, but Gi-hun offers the marble Il-nam gifted him in the previous game. Gi-hun and Sae-byeok pass the marble to Sang-woo, who gives it to Player 017. However, after tossing the marble on the next left glass tile, 017 asks for another marble to throw on the right tile and says he is still not sure what is the correct one to step on. Sae-byeok, Sang-woo and 017 turn and look expectantly at Gi-hun, hoping for more marbles. But Gi-hun informs that he doesn't have anything else with him.
When there is less than 20 seconds left, Player 017 is squatting and looking between the next two tiles, still unsure what is the correct tile to step on. Sae-byeok and Gi-hun are then shocked to witness Sang-woo jump onto 017's tile and push him towards one of the next tiles, having cited repeatedly that they are running out of time. This makes the glass maker break the last normal glass tile and fall to death, but it also reveals the last tempered glass tile. Sang-woo jumps to the last tempered glass and then to the platform on the other side, finishing the game with ten seconds left before the time is up. Looking at the timer, Sae-byeok quickly decides to follow Sang-woo. She and Gi-hun rush while hopping on the last tiles to get to safety, with Gi-hun jumping on the platform just as the timer expires. Once the time is over, the trio is surprised by all the remaining glass tiles suddenly exploding. They are all hit by the glass shards, but Sae-byeok is the only one gravelly wounded by a huge chunk of glass which pierces her left hip. After being hit, Sae-byeok is behind Gi-hun and Sang-woo, she looks down at her wound in horror and trembles, but the two men fail to notice.
==="Front Man"===
Following the Glass Stepping Stones game, the three last players are escorted back to the dormitory by two soldiers. Sae-byeok goes down the spiral staircases following Gi-hun, with a soldier walking behind her. Mortally injured in the game, Sae-byeok bleeds as she walks, leaving a trail of blood in her path. Despite this, she endures the pain in silence and holds her wounded left hip with both hands, trying to stop the bleeding. Arriving at the almost empty dormitory, she limps back to her bed and sits alone while Gi-hun starts to argue with Sang-woo about Player 017's death. Soon, they all see the masked staff entering the room carrying gift boxes. The manager congratulates them for winning five games and becoming the three finalists of the Squid Game, then says that a gift was prepared for their status. But before revealing the gift, the players need to change into the outfits the staff prepared for them, so the trio is offered the gift boxes. 
Right after, Sae-byeok goes to the bathroom by herself. In front of a sink, she takes off her shirt and checks the state of her wound. A large shard of glass still pierces her left hip. Sae-byeok painfully removes the shard, losing a lot of blood in the process, leaving the bathroom floor covered in red. She tries to stanch the blood with toilet paper while ripping her shirt and then wrapping it around the wound. After washing herself, she decides to open the gift box that the masked staff gave her and finds a tuxedo inside.
Later, Sae-byeok dresses her new formal clothing and is part of a fine dining in the dormitory, which is the reward that the staff prepared for the finalists. The lights are out and the workers lit candles to illuminate the room. Each of the players sit at three long tables, which were arranged to form a triangle, while they are served dinner. Sae-byeok and the two men are each served with a large steak and wine. She initially just stares at her food, but starts eating after seeing the two men doing it. Because of the wound and the blood loss, Sae-byeok is very pale and barely manages to eat, which is noticed by Gi-hun. She looks at Gi-hun upon noticing him staring at her, but they both remain silent. As they all finish eating, Sae-byeok is the only one who leaves a large portion of her food on the plate. When the dinner is over, the masked staff collects their plates and utensils, but leaves each one of them with a steak knife. Sae-byeok and the two men look nervously at each other, before the three of them pick the knives and keep them with themselves.
After the dinner, each of the finalists sits on their respective beds holding their knives instead of sleeping in the candlelit dormitory. Sae-byeok struggles to stay awake. She dozes off and is startled when Gi-hun approaches her, making her hold her knife to defend herself. Gi-hun tells her that he didn't come to kill her and if he wanted to, he would have already done it because she was almost asleep. He holds up his own knife and tells her that he only brought the knife to defend himself from Sang-woo and puts it inside his pocket to show that he means no harm to her. Gi-hun sits next to her and says that he noticed that she isn't looking too well, but Sae-byeok denies it. He asks why she barely touched her food during the dinner. Sae-byeok replies that the food was not very good, but Gi-hun tells her not to lie. Sae-byeok says that even if she is hurt, he wouldn't be able to treat her. Sae-byeok tells Gi-hun to care about himself.
Gi-hun suggests that the two of them work together against Sang-woo in the last game. Gi-hun says that he and Sae-byeok could win the Squid Game together and share the prize money. They have a conversation about their families. Sae-byeok asks what Gi-hun will do with the prize money if he survives. He reveals he will pay off his debts, then open a business up a business at the marketplace for his mother, who always wanted a proper store instead of a street stall. Gi-hun also tells her that he wants to be a good father to his ten-year-old daughter. Sae-byeok realizes that Gi-hun's daughter and her little brother have the same age. When Gi-hun asks where her brother is, she explains about her promise to get Cheol out of the orphanage and about bringing her mother to the South, and that she wants the prize money to buy a house for them. Gi-hun tells her that with half of the prize, she will have more than enough money to make her wish come true. Sae-byeok asks him to promise that if either one of them manages to survive and win the game, they will use the prize to take care of each other's family. Gi-hun tells her not to say this, certain that they will defeat Sang-woo and leave the games together. Sae-byeok, however, insists that he promise to take care of Cheol.
Gi-hun then notices that Sang-woo is sleeping on his bed and moves towards him holding his knife, with the intent to kill. Sae-byeok stops him, saying that he shouldn't do it because he is a good person. As Sae-byeok reclines against her bed frame in pain, Gi-hun runs back to her. Upon opening her jacket, he finds out she is bleeding profusely under her tuxedo. Gi-hun wonders when she was injured and puts both hands on the wound while trying to stop the bleeding. Sae-byeok last words to him is that she wants to go home. He sees she is almost passing out and begs her to stay awake while he calls for a doctor. Gi-hun leaves a dying Sae-byeok on her bed and runs to the doors of the dormitory. Gi-hun bangs on the doors and screams for the guards outside to help the girl, but this ends up waking Sang-woo up. Realizing that Gi-hun might attempt a vote to stop the games and save the girl, Sang-woo gets out of his bed and stabs Sae-byeok's neck while Gi-hun is still banging on the doors.
When the lights come on and the masked staff finally enters the room, they come carrying a coffin to take away Sae-byeok's corpse. Gi-hun turns and sees Sang-woo near Sae-byeok's bed, realizing too late that his childhood best friend had killed Sae-byeok while he was calling for help. Gi-hun runs towards Sae-byeok and kneels on her bed, which now has the white sheets soaked in blood. Gi-hun holds Sae-byeok in his arms, seeing that the girl now has an open wound on her neck. Devastated, Gi-hun repeatedly calls Sae-byeok's name and cries over her body, mourning the loss of the girl who had become his close friend.
Becoming enraged by the murder, Gi-hun lays Sae-byeok's corpse back on the bed and turns to Sang-woo, who is still paralyzed and staring at nothing near Sae-byeok's bed. Gi-hun grabs his knife and tries to attack Sang-woo in retaliation for what he did to Sae-byeok, but is stopped by a soldier who pins him to the floor. While being held down, Gi-hun cries as he sees two soldiers put Sae-byeok's lifeless body inside the coffin. Sae-byeok's coffin is later shown being carried by the soldiers to the furnace, where she is cremated.
==="One Lucky Day"===
Despite not appearing in the final episode of the season, Sae-byeok is mentioned several times. During the final game, Sang-woo says that Sae-byeok was going to die anyway, so he just ended her pain quickly by killing her. Gi-hun, however, disagrees and believes that Sae-byeok could have been saved. Sang-woo states that the main reason why he killed Sae-byeok was because he knew Gi-hun would attempt to give up on the games to save the girl. In case of a vote, Sang-woo feared that both Gi-hun and Sae-byeok would vote to end the Squid Game, causing him to go home with no money. Enraged that Sang-woo killed Sae-byeok to prevent a vote, Gi-hun reveals that Sae-byeok stopped him from killing Sang-woo in his sleep last night.
Ultimately, the final game ends with Gi-hun as the winner after Sang-woo decided to commit suicide for his friend to take the money. Despite having the prize, the games leave Gi-hun traumatized to the point that he doesn't even touch the money for an entire year, because it is a reminder of everyone who died in the competition, including Sae-byeok.
In 2021, one year after the events of the 33rd Squid Game, Gi-hun finally decides to use the money and fulfill the goal Sae-byeok entrusted to him in the end. He visits Cheol in the orphanage and notices how similar the boy is to his older sister. Cheol is surprised that Gi-hun knows Sae-byeok, so Gi-hun explains that he is her friend. When Cheol asks if Gi-hun knows where his sister is, Gi-hun becomes sad and does not respond, not knowing what say. A picture where Sae-byeok is smiling beside Cheol is seen at his bedroom in the orphanage. 
Gi-hun takes Cheol out of the orphanage as Sae-byeok wished, then puts him under the care of Sang-woo's mother. After asking his friend's mother to take care of Cheol, Gi-hun gives her a suitcase with a fair share of the prize money (fulfilling Sang-woo's dying wish). 
Category:Synopsis