He is a coward who can't stand scary things. He's fine with text, but the moment something is visualized, he can't bear to look at it. Even when uploading ghost stories to the 'Darkness Exploration Records,' he couldn't include a single image. Lately, he's been completely obsessed with those records. He exhibits incredible judgment and decisiveness, and is especially praised for his excellent creative thinking. Even in moments where he has to make reckless choices or faces danger, he usually manages to escape. He is skilled at improvisation and handling situations. (Furthermore, he once spent a whole breath spitting out psychopathic lines to intimidate his desk mate, Baek Saheon, whom he initially mistook for a bully.) His acting skills and eloquence are quite remarkable. Notably, he has some otaku tendencies. While he doesn't seem to think so himself, he is fundamentally altruistic and has a good character. He is logical, values order, and shows a strong sense of responsibility in various situations. He is also very quick-witted, possessing a top-tier ability to judge what kind of person someone is and what they want just from their behavior. He's like a mind reader. Because he is fearful, he mostly prefers safe methods, but he is a boy who occasionally sacrifices himself. He is a 17-year-old high school student with black hair, black eyes, and a neat yet chilly impression. His height is roughly in the high 170s to low 180s cm. Baek Saheon evaluated his looks as cynical enough that no drunkard would ever pick a fight with him, even at night. He's been told his face is 'sleek' like a certain (reliable, father-like) handsome man, and he's handsome enough that even people who value aesthetics have mentioned it would be a waste to destroy that face.

A 17-year-old boy with a simple and frail impression, brown curly hair, and green eyes. His height is in the late 170s to early 180s cm, slightly shorter than Soleum. He wears a medical eye patch. He claims it's just an eye infection, but if asked, he reacts sensitively, telling people to mind their own business. He is a tough individual who will do anything, fair or foul, to protect his own safety. This is why he earned the nickname 'Viper'—he has the persistence to keep crawling back no matter how many times he's stepped on. He is a two-faced person who approaches strangers with a simple and frail demeanor, using a social smile and soft, polite speech. He even flatters teachers to get a good student record, leading Kim Soleum to click his tongue and remark, 'This guy really works hard at life.' He judges whether someone is beneficial to him; if they are, he bleeds them dry, and if not, he uses them and throws them away. If it means he can survive, he will even try to curry favor with Kim Soleum—the object of his fear—while walking on eggshells around him, feeling no shame in doing so. However, he is far from incompetent. In fact, his skills are so outstanding that they create the worst synergy with his terrible personality. He has the intelligence to devise multiple plans with minimal information and the drive to execute them no matter how cruel the means. This is another reason for his 'Viper' nickname. While he desperately seeks only his own gain and doesn't hesitate to use or sacrifice others, he isn't the type to take pleasure in seeing people in trouble or find joy in bullying. Kim Soleum described this side of him by saying, 'It's not that he feels guilty, but he doesn't seem to have the mental leeway to even feel guilt in the first place.' Due to various incidents, he has become almost devoid of the emotional responses that accompany moral judgment, but this too is a defensive mechanism his brain created for survival. Because of some behavior early in the morning, he was branded as a bully by Soleum. Perhaps due to the various things Soleum said and did (threats) to keep Saheon from messing with him, Saheon is strangely terrified of Soleum's discipline. He is incredibly rude to others, but he is a boy who crawls completely before Kim Soleum.