The exposition includes Chapters 1-10 of the webtoon.
Hyung Suk's mother asks him if he's okay and scolds Tae Sung, which attracts the attention of some of Hyung Suk's female classmates who make a few comments about him. Hyung Suk, trying to calm his mother down, attempts to reassure her by stating that it was 'just a game' but this just angers his mother even more and she starts hitting Tae Sung repeatedly. Hyung Suk's female classmates continue making comments and this embarrassed him, leading him to become enraged. He then furiously yells at his mother, stating that she is embarrassing him and Hyung Suk apologises to Tae Sung. This secretly makes Hyung Suk feel miserable and he even called himself the 'world's biggest piece of trash'. After school ended, Hyung Suk was hesitant to go home but decided to slip into his room with a snack without his mom noticing. His mom noticed him anyway and made him sit down, talking to him about how he should transfer. Hyung Suk realises that his mother knew that he was getting bullied but pretended not to know. His mother reassures him that he doesn't have to worry about the financial expenses and he should just go away from his bullies so he can be happier and study better. Hyung Suk had his mixed emotions all tangled up and starts sobbing relentlessly.
Despite feeling guilty of leaving and ignoring his mother's burden, Hyung Suk listens to his mother and leaves with a bright, cheerful smile. He feels gladdened that he'll be able to start fresh and hopes that he can make some new friends. Hyung Suk finds his new home which turns out to be an old shack but feels happy and appreciates it, knowing that he'll live a newer and better life. Hyung Suk goes to the hair dresser and has his hair cut to a 'two-block' hairstyle. Afterwards, Hyung Suk thinks that his haircut makes him look very handsome and tough, but nobody else seems to think so since he looks strikingly similar to Kim Jong Un. When Hyung Suk finds Mi Jin looking at him, he thinks that she is interested in him, so he smiles at her. Jin Sung sees Hyung Suk smile at Mi Jin and thinks he's propositioning her. He confronts Hyung Suk, and may have gotten into a fight if Mi Jin had not steered him away, telling him not to act aggressively in public. While walking away, Mi Jin smiles apologetically at Hyung Suk for Jin Sung's behaviour. However, Hyung Suk takes the smile for flirting and asks Mi Jin and Jin Sung out for coffee. Unable to keep his anger under control, Jin Sung punches Hyung Suk in the face while bystanders take pictures and upload them online.
As shown in his new house, Hyung Suk is found crying and he continues to cry himself to sleep. When he wakes up, he casually goes to the bathroom and finds that the ceiling and sink look much lower than before. He then finds himself looking very different, with a slim figure and extraordinarily handsome appearance. He stays in utter shock before falling out of the bathroom in confusion and bewilderment, only to find his old body which is found to be sleeping peacefully on the floor.
Hyung Suk, in his new body, ponders on who he should tell about the current situation and he finally decides to rely on himself. He attempts to wake his old body up but after failed attempts, Hyung Suk forcefully wakes his old body up with a harsh slap. He then wakes up in his old body and after a while, he learns that when one body is awake, the other body has to be asleep and that he has to come up with an even schedule. He finally decides to be in his new body during daytime while being in his old body during nighttime.
The next day, two schoolgirls are shown commenting on the looks of some of the schoolboys and they compliment Beom, stating that his dyed hair looks cute. Beom secretly hears this as he walks by and stays pleased, thinking that 'it's his time to shine'. The girls continue talking about boys they found attractive and when Hyung Suk (in his new body) walks by them, they become awestruck and they start blushing intensely. Beom is seen admiring his reflection, commenting on how handsome he looks, and Hyung Suk accidentally bumps into his shoulder which irritates Beom. Beom turns around in annoyance to see who bumped into him but when he sees Hyung Suk's face, he becomes shocked and speechless. As Hyung Suk walks on the school campus, more people notice how extremely good-looking and handsome he looks and they all stay absolutely speechless. A girl sees him and excitedly runs up to him, checking his face and states that he's a ten. Hyung Suk, unaware of the expressions of the people, hopes that he doesn't get bullied like he did before.
This chapter starts off in a classroom, where people are casually talking about how time flies so quickly. Hyun Do and his friends are talking about the immense heat and Hyun Do's friend commands Ji Ho to bring the power level of his fanning to 'level 3'. Ji Ho reluctant agrees because he has no choice and fans the three of them, secretly thinking about how humiliated he feels. A girl states that it's too cold and that they should stop but because they find her very unattractive, they insult her rashly. Mi Jin shivers and states that it's cold. Because she is very beautiful and attractive, they immediately stop the fanning which makes the first girl feel rather upset. The homeroom teacher comes in and tells everyone to be quiet, stating that there's a new transfer student. Everyone becomes curious and wonders whether they're a boy or a girl. Hyung Suk, being the new transfer student, enters the room and everyone becomes astounded at his attractiveness. Everyone thinks that he looks absolutely gorgeous but he doesn't seem to notice this. The girls' hearts race while the boys become slightly alert and jealous of his appearance.
Hyung Suk goes to his assigned seat and tries to make friends with whoever is next to him, so he smiles and greets whoever is next to him. To his shock, Hyung Suk realises that the person sitting next to him is Jin Sung, the boy who punched him earlier. Hyung Suk becomes extremely nervous and anxious while the rest of the class thinks about his striking appearance and how handsome he looks, including Jin Sung. Ha Neul drops a blue cloth which was wrapped around her waist to unveil her legs and revealing skirt and starts walking over to Hyung Suk. She introduces herself and starts flirting with him, which angers the other female students in the class. Hyung Suk becomes embarrassed since this is the first time someone has flirted with him but Jin Sung casually tells Ha Neul to sit because her flirting is annoying. This secretly exasperates Ha Neul but she stays calm and teases Jin Sung, trying to look good in front of Hyung Suk. Jin Sung turns around to see Mi Jin staring at Hyung Suk in awe and he becomes enraged, thinking about how much he's starting to hate Hyung Suk.
The next scene is set in the cafeteria, where Hyung Suk is serving himself lunch with Ha Neul next to him while everyone else, being absolutely awe-struck at his attractiveness, gazes at him with shocked faces. This annoys Ha Neul and she looks around to fend off the stares as she wants Hyung Suk to be hers and hers only. Hyung Suk, unaware of the situation, just thinks about how he doesn't have to serve others and becomes moved and happy. Hyun Do and his friends overhear the whispers of the people about Hyung Suk and his attractiveness and they become alert. They go to him and state that he needs to meet them after lunch, which worries Hyung Suk. Hyung Suk reluctantly listens and meets them after lunch, being frightened and worried that they might bully him and attack him like the school delinquents, in his old school, did before. Surprisingly, they offer him a cigarette and say that he must be a 'ladykiller' and that he should hook them up with some girls. Hyung Suk lies to them that he quit smoking (so that he doesn't have to smoke while not making himself look 'uncool') and informs them that he doesn't know any girls. The three other boys, including Hyun Do, feel intimidated and think of Hyung Suk as imposing while Hyung Suk quickly runs off in fear. Later, Hyung Suk is seen peacefully sleeping with Ha Neul watching him adoringly.
Hyung Suk wakes up in his old body and panics, trying to force himself to sleep while angrily swearing. Ha Neul slightly pushes him and this forces his new body to wake up and he accidentally swears while doing so because he kept swearing in his old body. This greatly shocks Ha Neul because it seems like he is swearing at her and the rest of the class is amused that he's 'telling the skank off'. Ha Neul seems displeased at first but it turns out that she likes him even more now.