|Before and after Dicership|
Che-hyun is a student in the protagonists' school, though one year younger than they. He is an A-Ranker of unknown skill and has shown a cooperative stance towards Dongtae so far.
Che-hyun was originally very obese, and as a Dicer has become thin and well-proportioned, but other than that his looks remain unchanged: he is a blond, short-haired kid with grey eyes. He was taller than Dongtae originally, but is now shorter. He always wears a red jacket. He seems to have remained quite the heavy eater, but his metabolic rate prevents him from becoming fat again.
(In chronological, rather than narrative order)
Che-hyun and Dongtae become acquainted in comic fashion. When the latter was still a bully victim, Che-hyun very often bought all the cheeseburgers Dongtae had been ordered by his bullies to buy for their lunch, and as a consequence Dongtae ended up being beaten up. Originally, he thought Che-hyun was a bread shuttle too, in view of the amount of cheeseburgers he bought, and was shocked to find out that the kid had been buying everything for his own consumption, all the while ignorant of Dongtae's predicament. Che-hyun was decent enough to offer Dongtae a cheeseburger as a token of friendship, but that was the end of their contact for a long while. This happens as a flashback in the story.
After becoming a Dicer and an A-Ranker, and when the PVP stage is already in progress, Che-hyun first appears in the story as an spectator in a PVP battle between B-Rankers, and later he analyses the events as the fight between Dongtae and Taebin unfolds, accurately predicting Dongtae's victory. He then follows Dongtae and approaches him after he leaves Mio's flat. He pretends to meet Dongtae accidentally by grabbing, in reminiscence of their first acquaintance, the last item of a food product Dongtae intended to buy. To his upperclassman's utter shock, Che-hyun follows by hugging Dongtae warmly as if the two had been longtime friends.
They strike a conversation for a while but then Mio, who had seen Che-hyun stalking Dongtae, phones him to warn him about the kid, and Dongtae follows up by almost starting a fight. Che-hyun defuses the situation just in time and proceeds to discuss PVP strategy with Dongtae. At this moment, X announces the War Quest.
Dongtae asks Che-hyun to choose Defence, but in the day of the Quest, Che-hyun appears late while Dongtae is having a rough time against Hood, and apologises both for his tardiness and for having chosen Attack, in his words, "by accident". He then throws a Dice Bomb to distract Hood while he tosses three ordinary Dice and one Enchant Die to Dongtae, who at this point cannot even activate Time Pause due to having exhausted his own Dice.
Dongtae declines to use the Enchant Die in order to prioritise the evacuation of all B-Rankers from the area. He stops time instead so all can escape. Che-hyun tells Dongtae to keep the Enchant Die and the two, plus Hyunjo, proceed to the school office to find out the identity of the second target, Chun Nobong.
Che-hyun has a mischievous, light-hearted personality. He can be nosy and cause embarassment to others, and when there is food involved, he can be quite indifferent to his surroundings. However, he is also cunning and being a gaming addict, he is quite good at reading situations and devising effective strategies, easily predicting the outcome of a battle between Dongtae and Taebin. He realises the advantage of keeping his A-Rank skill hidden even before the PVP stage, and keeps his cards close to his chest, although he is averse to fights.
So far, strategy seems to be what Che-hyun excels at. He is good at causing diversions and devising plans. His A-Rank skill is not known yet and if he has enhanced any of his physical or intellectual traits, that has not been revealed yet.
Although not specifically stated, Che Hyun is seen using an ability that appears to be an upgraded version of Clairvoyance, using an invisible dice with an eye to monitor peoples' activity like a surveillance camera and also being able to see other people's heath and status over the monitor.