Jay Jo or Jo Ja-Hyun (Hangul: 조자현) is the main character in the Webtoon series titled Wind Breaker and attends Sunny High School. At the start of the series, he was presented as a studious introvert individual. As the story progresses, he gains a group of friends who all share a love for biking and he learns to open up. His debut in the League of Street preliminaries helped him gain popularity in the biking scene in Korea as well as at school.
Jay is a young man with short, straight black hair cut into a mullet. He usually assumes a serious and emotionless expression. He is cold hearted, but very much so cares about the friends he has and his little brother. His minimal expression of emotion doesn't allow him to articulate his feelings very well, but sometimes his few words mean a lot. His typical school uniform consists of dark trousers, a white shirt, and a red blazer. His casual clothes is composed of a variety of T-shirts, hoodies, and sportswear. Since he is farsighted, he wears glasses, except when riding or racing with his bike. Later in the Webtoon, he is mostly shown not wearing his glasses, and also has a skin fade from his sides and keeps it long from the top.
Jay is perceived as a very serious person and is often mistaken as selfish, arrogant, and stubborn. He didn't have many friends because his parents taught him that friends were unnecessary, and to only focus on his studies from a young age. As a result, Jay became very introverted, stoic, and studious and often keeps to himself. However, as the story progresses, it is shown that he is also quite caring, understanding, and selfless. This is demonstrated by how he treasures his time with his friends. Once in the past, he gave Mia his spare pair of glasses after hers was destroyed by bullies. He also chased a thief riding a motorcycle who stole Shelly's wallet that later led to another encounter. On top of all else, he is also shown to be determined through his training, as well as a fast learner, even teaching himself how to do Owen's lean In trick.
Despite his emotionless personality, Jay expresses more of his feelings over time, as he spends time and interacts with his friends, even revealing out loud that he liked Shelly.
Jay did not have much of a childhood and was always studying, even on his birthdays. Jay's parents hold extremely high expectations for him when it comes to academics to the point where he's not allowed to have friends as they would only distract him from his studies. His parents told him that he can have fun after he attains a stable and successful career for himself. When Jay was younger, the only time he wasn't studying was when he was with his uncle, Mach Jo. On his 13th birthday, Mach gave his bike to Jay promising that they would one day go on a cycling trip together and that Jay was to practice cycling until then. Unfortunately, his uncle died before that could happen. Jay loved his uncle dearly and would often think about him, and those memories would remind Jay why he loved cycling. While Mach was still alive, he asked Jay about his dream and Jay responded that he wanted to be a doctor. However, Mach knew that this response was actually the expectations Jay's parents had pushed onto their son. He then asked Jay what his real dream was. Mach's influence on Jay went on fuel Jay's passion for cycling.
Years later, Mr. Nam prompts his class, asking what they would do if they only had a week to live. Jay simply wrote down that he would like to go on a bike trip with his friends, something he was unable to do with his uncle.
At the beginning of the school year, Jay was always found by himself, studying. The only time he was around people was during student council meetings. The first time he was shown riding a bike aside from the prologue (Ep. 0) was when he made a downhill skid with his fixed gear bike. The Zephyrus Crew witnessed Jay's skills, including Minu and June who found out that he was Sunny High School's student body President. Minu proceeded to pester Jay into joining their crew and face off in a race against TJ. Jay finally agreed when Minu said that TJ had trash-talked Jay's bike and called it an "old piece of crap." Jay showed up to the race and won the game, which pissed TJ off.
Later, out of bitterness from his loss, TJ and his gang from Mountain High School kicked Jay's bike. Dom came and scared them off. They patch him up with band-aids and also let him watch 18+ pornographic, which was Jay's first exposure to such content.
After being beaten up, Minu assembled his crew and fought with TJ. Jay proceeded to participate in a match, although late, with June and Minu against TJ and two more members of the Zephyr Crew, that led to June and Minu being kicked out of the group. Minu stayed at Jay's house after a while.
Jay met Shelly on the way to a meeting for the Student Council. He helped her take back her wallet that was stolen by two people riding a motorcycle, he chased them using his bike and it ended up with his bike broken. Shelly picked up his identification card and called her grandfather, the principal of Sunny High, to let her go to the same school until she goes back to England. He went to a repair shop owned by Heri, the Biking show commentator on a biking stream called Paprika TV. Heri gave them the suggestion to create a group and join the "League of Street. ", a biking competition. At first, he was skeptical about the idea of joining a biking crew and the competition, but he changed his mind after realizing he'd get a chance to meet Sangho Choi, who trained with his uncle. He believes his uncle was not someone who would use dope to gain the upper hand in competition and wants to find out the truth by facing Sangho in the finals.
Jay, Minu, and June created a biking crew with Shelly and Dom. They named the group Hummingbird after seeing a Hawk Moth that looks similar to the said bird. Mia was the one who made the logo for the group and was asked by her to teach her how to ride a bike.
Yuna and Mia were taken by a group of guys and Dom rushed into the scene, followed by Minu and Jay. They fought with Vinny and other guys and they only stopped when Dom's father's workers came to their rescue. They did not know that TJ's group was filming the whole fight and uploaded the video online. The video spread the day after, leading to them being suspended by the principal. Jay was so shocked that he even fell down the kid's playground just by throwing a rock at him. Their suspension, however, was a chance to practice for the upcoming competition. Principal Nick promised to end their suspension if they were able to complete his training. They were task to drag a tire behind their bikes and ride up a hill. They all had to make it together but Dom was lacking the basics and could not get up the hill. Shelly came and brought Jay drinks and snacks. He shared them with the boys after feeling their envious stares. When Shelly scolded Dom and Minu for dragginf Jay into their mess, Jay was quick to defend them and told her to screw off. After the three of them succeeded to go up the hill, they were given the extra task to cheer up Shelly because "someone" made her depressed. In order to get back to school, they had to go cheer her up and get her to go to school. Jay talked to Shelly, but because of his inability to express himself, he failed. Then, Shelly asked a favor from Jay. In exchange for her forgiveness, he'd have to become her boyfriend for a week.
On their way to Heri's bike shop, they spotted Vinny riding a bike. The next day, they came to school and finding out that Geunho Na replaced him as the Student Council President, although the guy was ignored by Jay. A new teacher, Mario Nam, also came and expresses his interest to Jay. Sung, Vinny's friend came to Sunny High to talk with Minu and helping Vinny. When asked if it's okay to let Vinny join the crew, Jay expresses his lack of care. The crew plus Mia and Yuna meet at the park where Jay was supposed to teach Mia how to ride a bike. Minu also invited Vinny to come, which he did, Mia gave Vinny one of the Hummingbird's uniforms, a hoodie with the crew's logo. That's when the crew was completed.In a special episode, Shelly was seen riding a bike in Jay's neighborhood. Minu and Kay noticed her, Kay was thinking of who might Shelly go out with and ended up being shocked that it was his brother. In the last scene, Jay and Shelly are resting after riding their bike together, and her commenting that Jay suits biking more than studying and asking him if it was exciting thinking of racing with everyone and Jay answered "Yeah."
The first scene in Part 2.1 starts with Jay being scolded by his parents, mostly his mom, because his rank dropped to 12th place, formerly being the 1st rank. He got pretty bummed out and acted quite weirdly in the morning. They got called to the Principal's office about the preliminaries that are starting soon, after that he left the group and was drowned in his thoughts of his parents' words. He didn't do much in the first game of the preliminaries, instead, Dom was the one who became the crew's representative and that made them last on the list who entered the first round. Jay got pretty annoyed at Minu and June who teased him when he gave Dom an energy drink.
Jay volunteered as the crew's representative in the second round, maybe because of how another competitor talked bad about his crew and bike again. The second round is a corner race on a mountain road, this round garnered a lot of attention to Jay's ability because of his drifting tactic with a fixed gear bike, he also did inertia drifting. This made him popular in the competition and to the audience.
"That's true. He may be more than a beast than a monster himself." -Minu about Jay's biking ability
His birthday then came up and he was brought to the club that Dom's father owned, they celebrated it and also gave him a gift. It was a helmet that he uses for the next races. Jay was supposed to be pranked by the boys by spiking a drink, instead Shelly drank it accidentally and she spoke to Jay afterward, saying he should be nicer to her while she still likes her. She gets on the table, crawls towards Jay, and gives him his second, third, and fourth kiss. When Jay got home, he and Minu were arguing, which even lead to his brother thinking they might be in love with each other. He turned his brother's tv program off when it showed a kissing scene. Minu commented to himself that Jay is "aware" of what happened. The morning after at school, he's still shaken up. Absent-minded by the kiss, Jay kept on wearing the helmet until their teacher makes a comment about it. While playing basketball, he just stood in place holding the ball. Shelly cheered him on and also told him that she'll give him another kiss shocking him to drop the ball.
Jay replaced his tires with new ones and Minu came to talk with him. Minu told him that he and Shelly should just go official but he answered that he's not interested in dating yet and he was asked if he doesn't care that she kissed him. It seems like Jay has a little bit of affection for Mia because of the way he reacted to Minu's words.
Kay, remembering that the race was on, watched it on the television, instead of studying. Their mother questioned if Jay was on tv and Kay denies it. Unfortunately, the announcer said Jay's name loud and clear and Kay was no longer able to hide the truth from their mother.
The third race was a duo race, and whichever team has one of their riders cross the finish line first is the winner. Jay volunteered again and then Vinny also volunteered, saying he wants to ride with Jay. The whole race turns into them racing against each other, they even block each other at one point. They both rode fast on a steep slope, Vinny slowed himself by stepping on the back tires but Jay still rode forward and did the same trick he did on the first race with TJ. He stops after realizing his tires were close to wearing down and left Vinny to win the race for the crew in the end and entering the competition officially. He then receives a call from his mother telling him to come home.
Minu gets home to see Jay's mother leaving for work and sees Jay with a red cheek, he kept on asking but Jay didn't say anything until Kay apologized. Jay just patted his head and told him that Kay was just trying to cheer him on and disregarded it. Jay and Minu meet Juhwan Jang on the bus when they took it to go to school because it is raining. The Hummingbird Crew then talked to Jay about his plan to withdraw from the team, her mother even called Mario Nam, the PE teacher, and talked to him about the competition and how they should withdraw Jay. Jay told them that his grades are more important than them and Dom asked him if he means it, the talk ended and he didn't go to practice, instead, he only studied.
Mario Nam came into the class and told them to write what they will do if they only have a week to live, Jay wrote that he wants to go cycling with his friends, later it was found out that his mother chained his bike on the storage room. He was walking home with Mia when they encountered Hwangyeon, Sangho's brother and also a competitor, with the Ghost Crew, he told them that he gave up on cycling already and they walked away when a guard showed up, Mia and him talked about him giving up on the way home. Jay ended up overworking himself on studying and got a nosebleed, on the day of the competition, he asked a teacher if they could let him take all of the tests at the same time. He did take them and was actually planning to ride his bike so that he could catch up but a man gave him a ride to the bike race.
The first race for the finals was a baton race, which started of with Shelly, Minu was waiting for her to mark the guy she was racing with and ended up on her leading the race and passing it on to June who is responsible for the uphill course, the next course was a straightway and the baton was passed to Dom. But an athlete from the opposing theme took a doping drug and was able to shorten the distance. Dom gave the baton to Vinny, however, since Vinny hurt his wrist which is vital to balance his bike, he crashed on a sharp turn road. That is when Jay came shortening the distance against the guy who was doping. He won by overtaking the race inside the tunnel and riding on the very side. He came out first out of the tunnel and won, by the end of the match, he fell down and was actually sleeping.
He woke up at the school's infirmary and was told that Dom, Minu, and Shelly are taking the exams in the next room. He came and told them good luck, he was then praised by their teacher and told him that he was a fan. Jay was then baited by Hwangyeon into racing him. He blackmailed Jay with pictures of Mia that insinuated she was drinking underage with the photographer and Hwangyeon. When he was about to go his mother caught him and reminded Jay that he should just be focusing on studying instead and should quit biking. If he did go, he was not welcomed to return home again. Jay still went and met with Hwangyeon. Hwangyeon said that he won't spread it if Jay won and raced against him. Jay won the race by riding with a car to shorten the distance, when Hwangyeon tried to joust an umbrella into his tires but Jay was able to shift his bike to the side and Hwangyeon ended up crashing, allowing Jay to win their race. Because his mother kicked him out of the house, Jay decided to stay at Vinny's house. Minu tagged along because staying at his house without him felt strange.
The next morning the pictures were spread on social media. The guys suspected Jay to post the pictures because of the USB that Vinny found, it was given by Hwangyeon that contains Mia's pictures, when they found out that it was the Ghost Crew, Minu, Dom, and Vinny fought with the guys but the cops came before it got too serious. They all ran away and when Minu was about to get caught by the cops, Jay came wearing a facemask to help him escape. Minu, Dom, and Jay slept at Vinny's house.The next race came up and Minu, Dom, and Vinny woke up and smelled something from the kitchen, Jay was cooking for them. Shelly didn't participate in the race, instead, she stayed with Mia and Yuna at school, it's because Minu, Dom, and Jay asked her to accompany Mia but she is actually worried about her too and that's why she did stay. The race was an elimination type, Dom and Minu were the ones who are competing and were placed at Team A which is composed of Monster Crew, Ghost Crew, and others. The Hummingbird crew finished at 2nd place and was even congratulated by Monster.
Jay has been missing for a month. He went up to the mountains to escape the survivor's guilt. He thought his friends hated him for not being able to change their current situation. While up in the mountains, he holed himself in the spare room and read. Some of the books scattered around him were Nicomachean Ethics, Crime and Punishment: World Classic Reading Book, Poetry with Sky, Wind, and Bee. Korean Literature, and Tale of Dreams. Shelly eventually comes up for him once she figured that's where he'd go. With Shelly now there and no more extra rooms, Jay and the monk raced their bikes down the mountain for the monk's room. On the way down, Jay remembers a conversation he had with his uncle about the merits of taking in the big picture instead of just being dialed in on a single detail. Coincidentally, Mr. Nam came up to visit the monk as well. Jay was forced to bunk with the two men when Shelly took the spare room. Their combined snoring solidified the fact that he could not stay there and he and Shelly made their way back to society in time for the first race after the 3 months break.
Mr. Nam confronts Jay, Dom, and Shelly after the race insisting that they won the last race due to luck. He invited the Hummingbirds to train with him and advised them to bring plastic bags so they don't throw up on the streets. When they meet up for the bike ride, Jay notices three extra freshmen and comments on how their numbers are growing. While biking Mr. Nam tells the freshmen that if they can keep up, they will become members of the Hummingbird Crew. When they reached their final destination, Mr. Nam barely gives them a break before making them do suicide runs for the two remaining spots in the house. Jay was not able to keep up his stamina against Dom and June. While settling for the night, he tells Shelly that she has a place inside and did not have to sleep outside with them. But she refused, not wanting to be given special treatment for being a girl. He is suddenly acutely aware that she's been texting a friend and asks about it. Shelly tells him that her friend from England plans to visit very soon and says they would get along. She says that she will introduce them later but Jay turns her down. Shelly slyly says it's because Jay was jealous but he denies the accusation. Outside the tent, Vinny hears their conversation and is reluctant to retire for the night, not wanting to be a third wheel. The next day, the crew is split into two even teams and raced an 800m relay, 200m strip for each member. Jay and Vinny are on different teams and race the final lap against each other. Jay manages to pull ahead during the final few meters of the race and wins.
When they get back to civilization, Shelly and Jay split and for the first time in a month, Jay goes to visit Minu. It was not a welcomed visit but Jay insisted that after they win their race, he would be back for a talk. Jay meets up with the team in time to see a punk attempting to flirt with Shelly and intervenes. Dom and June express their happiness now that Jay is back but Vinny is silent. During their race with the Punk Prince Crew, paces behind while the rest of the crew try to attack. It seemed like the lack of training during the last month hampered their teamwork. It seemed like Jay was far behind but according to the monk who was watching up in the mountains, Jay's riding has improved. When the collision happened right before the finish line, Jay does not slow down and instead used Chan's helmet as a ramp to maneuver over them.
Medal Breaker is a short spin off side story about a mysterious transfer student to Sunny High. He is revealed to be an Olympic shooter part of a secret organization that's training Olympians. The Hummingbird crew makes a few cameos in this comic. Jay is seen riding his bike inside the Olympic training building in episode 3. Minu, Dom, and Jay were seen again briefly in the courtyard during episode 7. Jay was reading a book while Dom and Minu were playing basketball. In Episode 7, while the KT associate trainees were heading up the mountain to meet the Master Monk, the Humming Bird Crew were seen racing down the mountain, presumably to get to the rematch in part 2 episode 115.
The first bike Jay rides is an unknown bike made out of chromoly steel that most closely represents the look of a NJS Samson, a hand-built Japanese fixed gear used in keirin races with a price tag of $700-$1000, but otherwise, it is very similar to NJS Samson except for the paint job and a few choice parts like a Sugino 75 crankset and chainring, Izumi super toughness, "arrow" carbon tri-spoke that looks like a spin tri-spoke repainted to white, a unbranded polished 40mm alloy rim, a Selle san Marco Concor leather saddle probably a Nitto pearl quill stem and a Nitto B123 dropbars.
Later in the story, he receives another one of his uncle's bikes, an all black LOOK 496 - two generations behind (newer ones are L96 and R96) carbon track bike, but as mentioned - still competitive. A mostly carbon fiber bike, the 496 is actually a velodrome machine, so the conversion of it from a track focused to a street thrasher type is necessary for the story to progress onward. This bike comes at a quite high price of $8000 and above for select variants.
- Mother - She's a doctor and also helped Vinny's mom. She is against Jay biking to the point that she threw his bike away. She wants him to study hard and told him to enjoy life later when he got a great job. She was shocked when her son rebelled against her. While watching the races, she smiled when Jay's crew was losing and was angry when they ultimately won. During one of his races, when Jay passed a mother and son on the street, the mention of studying from the little boy's mom triggers him into experiencing flashbacks due to the constant stress of his mother on his case about studying. When Jay came back home after going missing for a month, she gave him his clothes and told him that she has no son like him. He was eventually able to return home but she states that she doesn't want anything to do with him, believing that he is throwing away his future. Despite his estrange relationship with his mother, when Jay got a hold of the red capsule, she was the first person he went to, to confide about the contents of the drug.
- Father - Not much is known about his father but just like his mom, they have high expectations to their oldest son. There are also no intimate scenes shown in the series yet. Seems like he's pinning the blame of their son running away on his wife. He believes it's her fault for not caring for their children enough.
- Kay Jo (Brother) - They don't have any sweet relationship and not that intimate either, however, it is shown that they are quite close. He thought that Minu and Dom are gangsters and beaten up Jay, he pretended not to know his brother to save himself. Kay may also be the one responsible on marking Jay's birthday on the calendar. When Jay was caught by their mom because Kay was cheering and watching him on the television he didn't get mad at him. He also helped Jay entering the house by taking out a ladder through the window so that his older brother can sneak in.
- Mahon Jo (Uncle) - They had a very close relationship, he was the one who inspired Jay on riding a bicycle. At the time, Jay had no goals of his own, only the ones place on him by his parents. Mahon told him that it's his dream to stand on top of everyone and the world and told him that nothing's impossible. Jay watched him won the Tour De France and believed that nothing's impossible. Jay deeply respects Mahon and believes that he never willingly doped in a match. That's why he agreed to join the League of Streets to face Sangho, his uncle's friend and ask him in person what happened with his uncle. He also treasures both of Mahon's bike, the one gifted to him at 13 and the one that was given to him by Mahon's friend.
- Minu - Minu might be the closest to Jay in their friend group. Minu was the one who encouraged Jay to race. Because Minu lived in their house for awhile, Minu is aware of Jay's problem with his parents. Jay respects Minu and trust him especially when planning strategies for the race. Minu knows that Jay is a great biker and even called him a beast. He shows great faith in Jay's abilities and knows that he will win the second round of preliminaries despite of the other member's worries. Jay was deeply affected by Minu's accident, blaming himself for the accident. Unsure of what to do and feeling guilty for Minu's injuries, Jay runs away for a month to the last place he and their crew were happy, the mountains. When Jay hears of Minu's attempted suicide, he ran all the way to the hospital where we see for the first time in the series, Jay yelling for Minu in anguish. Minu holds a grudge against Jay for abandoning him but when he realised how much guilt he held for "not paying attention", he slowly comes to an understanding of Jay and his actions. They now have a solid friendship and Jay often visits and supports him during his therapy.
- Vinny - These two had a strong rivalry since the start. Vinny is often trying to compete with Jay, even during competitions against other crew. Vinny states that Jay is "kind of a freak" as well. He believes Jay enjoys the hunt because he always attacks from behind. They eventually warm up to one another though. When Jay believed that his bike got destroyed at the junk yard, Vinny tries to comfort him by offering up is home and provide ramen and rice. He understood the crushing hope Jay was feeling seeing his precious bike in pieces. Due to Jay's bad eyesight, he failed to realise the bike at the junk yard was not his but luckily, Vinny saw that it was a different bike. He chose not to inform the others until the bike was found. Vinny got the kids in his school to keep an eye out for the bike and was able to recover it from a fan of their crew. Despite now being good friends, Vinny still holds a bit of a complex regarding Jay that was developed after losing to him in multiple races. Jay is aware of the situation and tries to build Vinny's confidence by blocking their opponent and giving him the opportunity to win their group race against the Manga Crew rather than taking first place for himself. This makes Vinny more enraged because he believes Jay held back to let him win.
- June - Jay shows great respect for his senior. When they first met, he bows and acknowledges June's presence unlike how he acted towards Minu. June is shown to admire Jay's skills as a bicyclist and see him as the crew's ace. Likewise, Jay sees June as a reliable crew mate and friend.
- Dom - Jay has a good relationship with Dom. In their first race, while the others panicked about Dom representing the team, Jay was shown relaxed, even saying he wanted to read in the waiting room. When questioned why he wasn't worried for Dom, Jay states, "why the heck are you worried?" The crew believes that he just doesn't care but as readers, we understand how much it would mean for them to win. This insinuates that his statement shows his confidence in Dom's abilities and resolve. True to his beliefs, Dom was able to finish the race at the very last second despite crashing midway. Dom is able to tell the subtle differences in Jay's expressions and was able to see how happy he was receiving his uncle's upgraded bike. Jay has come to become protective of his friends. When Owen's crew mates approaches them and insults Dom, Jay is goes to his defence and immediately demands an apology from the tall foreigner.
- Shelly - Shelly was Jay's first and second kiss, it was quite clear from the start that Shelly harbors romantic feelings towards the guy. However, until recently, the same could not be applied to Jay. He kept pushing and disregarding Shelly's flirting and seems uncomfortable around her. After a few chapters, there relationship grows and they grew closer. Jay also became flustered after the second kiss, he turned off the television because it shows a kissing scene and he remains blank in school the next day, when Shelly shouted that she will give him another kiss, he dropped the ball that he was holding and remain shocked. When they are fighting group of guys, Shelly came and Jay instantly shouted at her not to come close and go. There are a lot of instances where it showed how Shelly clings to Jay and him not minding it. When she talked about going back in Europe, he was pretty upset.
- In the third season, the story often focuses on their relationship. Shelly was the one who found Jay in the mountains where the monk lives and where they trained before, he have to race with the monk so that Shelly could have a room. At night, her and Jay talked and it was hinted at the end that Jay slept on Shelly's room, just like what Mario and the Monk planned. When the race started again, a guy from the team they are racing with flirted with Shelly, Jay came between them and asked them what they are doing. While in the race, one of the members of the opposing team pushed Shelly to get past them and that made her lost her balance, before she crash on the ground, Jay moved beside her and helped her regain her balance. After the race, Shelly was on the phone, while Mia was talking to Jay, his focus shifted on Shelly to see what she is doing. When they are about to go home, Shelly accompanied Jay to his house, and when he was denied by his mother, she told her to come to her house and sleep there.
- They did nothing much, Shelly's asks him where he plans to sleep and he told her that he'll sleep in the sofa. When Shelly was eating some chips, Jay was staring at her and that made her blush, in the end he was just going to ask for some too and that made her pissed and whined about ruining the mood and when she was about to go he said thanks to her, her stomach growled that made Jay laugh lightly and Shelly threw her slippers in his face. Jay cooked something for her to eat. The morning after, the principal came on the house and was shocked to see Jay sleeping in the sofa, he asked the two of them how much progress they made that made the both of them flustered. Shelly got angry because her grandfather did not believe that they did nothing. She then accompanied Jay to his house again, Jay then was asked by his brother about what happened last night, and Jay dodged the question. Recently, Shelly's friend from England has made his arrival in Korea. his name is Owen. Jay and Owen have obvious tension due to the fact that they both have feelings for Shelly. Jay has never been good with expressing his emotions, but he has become more aware of Shelly's presence; especially with Owen around. When Minu tried to kill himself in the hospital, Shelly was found holding Jay in her arms as he cried. It seems like the crew and Jay's brother believes that they are together. In the latest chapter, Aria asked Jay if he likes Shelly and Jay confirms he likes her.
- Mia - They've known each other since middle school. She developed a crush on him when her glasses broke and he offered his to pair her. She was more like a silent admirer before Shelly showed interest in Jay, forcing her to be more forward with her advancements. We never found out if Jay held the same crush on Mia, but when Hwangyeon threatened to release photos of Mia in a compromising situation, Jay did not hesitate to agree to the race. In the end, it was all for naught because Hwangyeon uploaded the photos to his school's server anonymously anyway. Her crush on Jay slowly wanes as Minu shows her more attention.
- Owen - Rival for Shelly's interests. Owen arrives right as Jay is finally showing an interest in Shelly. He finds Owen annoying, but also in racing with Owen, he is finally able to see why his uncle enjoy racing so much.
Skills and Techniques
Jay is a well rounded cyclist. Throughout the competition, Jay is acknowledged as the ace of the crew. He is able to play as a defensive rider, supporting his crew during their races, as well as a offensive rider. Vinny noted that he enjoyed the "hunt" of attacking from the back.
One of his lesser acknowledged skill is his ability to sprint. It is often over shadowed by his crew mate Dom, but Jay has shown the ability to sprint at high speeds during races. During his race against Owen, he sped up on 3 different occasions. First at the start, then after Owen over took him, and lastly during the last leg of the race he made another burst to catch up.
- Inertia Drift
- Rock Wall
- Fish and Chips
- Railing Grinds
- Banked turn - mimicked Owen's lean with. "It's a skill that mtb riders would use in an off-road race or in mountainous areas."(part 3 ep76.)
- Cutty - In order to over take Noah during the turn, he changed his angle half way through the banked turn and race straight.
He memorised every possible route to the finish line to get ahead of Team Tarantula.
Natural Bike Sense
Years of practice results in his bike sense. Jay is so in tune with the mechanics of his bike, it's practically an extension of himself. He is capable of executing trick skills such as a stabbing break and rock wall without a second though. Jay possesses extraordinary technique with the bike. He shows great control manoeuvring around sharp turns. Often in races, he would accelerate, rather than slow down, during turns in order to execute drifts.
During his month long retreat to the mountains, he finally understood the meaning of his uncles' words earlier in his childhood. Jay learned to ride with a new sense of calm and the ability to read his environment with a wider lens.
He is gifted in picking up new skills relatively quickly. Shortly after getting defeated by Owen, he quickly picked up the technique, the Lean In, and used during his race against Vinny and Dom. During the 10th round Owen's crew mate commented on how similar his form was to Owen.
Mach Jo's Professional Bike (damaged) - gifted to his by his uncle's friend who got it as a last gift from Mahon before his crash.
Mach Jo's Training Bike (retired) - gifted to him when he was 13 years old by his uncle.
Delivery bike (retired) - Bought off an old man to be used for training purposes.
- Jay is bilingual in English and Korean. He could possibly be trilingual. If the English translation is canon, he may be proficient in French 
- Due to a promise he made to Owen Knight, Jay tried to shave his whole head after losing the match. Shelly stopped his endeavours to commit to going bald which resulted in his current do, a mullet with an undercut.
- Was ranked #1 in school academics
- At one point, his ranking dropped down to #12th place. He was forced to put his focus on his studies instead of his race and was able to reclaim his rank 1/362. On top of that, he helped the Hummingbirds win their relay after Vinny's fall during the last leg of the race.
- Loves wasabi and eats his barbecue with mustard
- Wasabi is his favourite flavour. All his snacks, even his sweets, are wasabi flavoured. When ate with Shelly at a squid and rice soup joint, he requested wasabi on the side to mix in his soup, much to the owner's disgust.
- Can sing well. Received a max score of 100 at the coin karaoke when singing Brown Eyes's (브라운아이즈) Don't Go, Don't Go (가지마, 가지마)
- Has zero artistic abilities
Anyone can try hard to reach a certain goal but not many people are persistent. If you keep trying at something, eventually you get the results that you want.
Jay to Dom