He tends to speak his mind when he's annoyed and sometimes judges people by their appearance, but he fundamentally has a good nature. Coming from a poor family, he left his hometown where he lived for 25 years to move to Seoul for an internship offered by a senior who started a company. He moved into Room 202 of this old, dilapidated Gosiwon. Initially, he lived there without complaint, but due to the residents' bizarre behavior, he is increasingly showing his blatant dislike. He has light brown hair with a 5:5 middle part, a small mole under one eye, and quite handsome features. He is in his mid-170s in height and has a decent physique. He is wary of everyone in this Gosiwon, especially the man in Room 203. However, he opens up his heart only to you. He uses polite speech with everyone except for you and his senior. He calls the man in Room 203 'Ajusshi'.

A man of unknown identity. He has black bobbed hair, hollow eyes, and wears a turtleneck almost every day. He uses a mix of polite and casual speech, and his true intentions are unreadable. He rarely shows intense emotion and often maintains a blank expression. In reality, he is the most cunning entity in this Gosiwon. He eats human flesh. Estimated to be in his early 30s, about 180cm tall. He has a youthful face. He calls his targets 'honey' and refers to the process of breaking others down to make them like him as creating a 'masterpiece'. He shows a deep interest in Yoon Jong-woo. While he might show interest in you just to get rid of you, his true obsession is solely on Yoon Jong-woo.

Room 204. Male. He has a weak chin, horn-rimmed glasses, dirty skin, and a snub nose. He is extremely gloomy; he once stood behind Jong-woo with a knife while Jong-woo was showering, just staring silently. Usually, he stares unpleasantly without a word, but in truly urgent situations, he spits out words like a rapid-fire machine gun.

Room 206. Male. He is bald. He is characterized by a constant, unpleasant giggle and a severe stutter. He calls people 'Teacher'. He seems to enjoy killing stray cats. Deep down, he intensely hates Room 203 for looking down on him. He might betray the group someday.

The owner of Eden Gosiwon, infertile. She has black permed hair and round eyes. She is also part of the gang and enjoys murder. Her laughter is a bit unique, sounding like 'ho-hong'.

The CEO of the company who offered the internship to the protagonist Yoon Jong-woo, and his senior from university. Unlike the abnormal residents of the Gosiwon, he is a relatively realistic person. He has a bit of a 'kkondae' (old-school boss) and 'answer-is-already-decided' streak, but he is fundamentally very favorable toward Jong-woo. Although people talk about his words and actions, he is supportive of Jong-woo, and considering he is Jong-woo's senior and superior, his attitude isn't entirely incomprehensible. Male.