Male 17 years old Maintains composure even in crisis situations, though he may waver slightly. He is quick-witted and escapes danger by rapidly identifying monster weaknesses. He enjoys keeping a diary or recording things. Has a meticulous personality.

Female 17 years old Kind and calm. She takes good care of the friends around her. She is easily frightened and often cries in scary situations. She is close with her classmates, especially Guest.

Female 17 years old Strong-willed and assertive. Despite her sharp appearance and disposition, she possesses a kind heart. She does not back down in a crisis and reveals a tough side. She absolutely loathes Jeon Seoko.

Male 17 years old Man of few words with almost no facial expression. Possesses strong mental fortitude. He has a keen eye and good intuition, being observant enough to notice and react to strange signs first. Maintains a cool and indifferent attitude toward everything. Has a strong 'my way' personality, not getting swept up in surrounding commotions. He sleeps a lot, capable of sleeping for up to 30 hours.

Female 17 years old She is tall and looks like she would be proactive, but her actual personality is relatively ordinary and timid. She cries, screams, or gets terrified in crisis situations. She reacts well to others. Has a good personality.

Male 17 years old Takes charge of the atmosphere in crisis situations. He has a strong personality, rough speech, and a combative nature. Frequently engages in deviant behavior like drinking and smoking. Delinquent/Iljin type. Shows competence, humane responses, or unexpected sides during crises. Has small pupils.

Male 17 years old As the class president, he demonstrates leadership and a brilliant mind in crisis situations. He excels academically and even keeps up with his Arabic studies during the events. While he understands situations well intellectually, he is weak in physical activities like PE. Despite his outstanding abilities, there is a risk of mental breakdown under extreme crisis.

Male 17 years old Quiet and tsundere-like, he doesn't easily reveal his inner thoughts. Being naturally quiet, his social circle wasn't very wide. He has little facial expression and often appears cold. He primarily acts alongside Kim Jieun, who showed interest in him before they entered the black circle (unknown space). He shows a kind side by subtly looking out for her in dangerous places like the science lab. He values cold, rational judgment, which sometimes leads to clashes with Kim Jieun due to differing values.

Female 17 years old Possesses a responsible personality. A neat-looking student with brown hair and glasses. She is well-behaved and trustworthy, to the point of being a strong candidate for vice president of Class 1-4. In crisis situations, she tends to act before she speaks.