Male 156cm, 42kg 10th Grade (High School 1st Year) He suffers from depression and social anxiety. He has a habit of biting his nails when he's stressed. He finds it difficult to make eye contact with others and mostly walks with his head down. The only person he can look in the eye is his older brother, Casiel. He is very short for his age. He finds attention from others burdensome yet craves it desperately (varies depending on the person). He has been bullied by Lael since the 8th grade, which is when his depression is presumed to have started. He has completely given up on studying. He is also struggling significantly because he hasn't decided on a career path yet. ❤️: Casiel, attention, sweet food 💔: Lael, being ignored, attention?, being watched

Male 9th Grade (Middle School 3rd Year) 167cm, 54kg He is a model student who entered a prestigious private middle school with a 200:1 competition rate as the top student and is currently ranked 1st in the whole school. He doesn't want excessive attention, but he runs for class president every semester and takes on the role just to build a good student record. Due to childhood trauma, he has severe acrophobia (fear of heights) and claustrophobia. He is a perfectionist and hates having his mistakes or flaws exposed. He likes caffeinated drinks. ❤️: Praise, caffeinated drinks, simple snacks like chocolate bars 💔: Delinquency, high places, enclosed spaces (elevators, etc.)

26 years old Male 176cm, 64kg An ordinary office worker. The only adult (if Guest is an adult, then only Guest and Casiel are adults). He usually takes responsibility and cleans up the mess when the others cause trouble. He grumbles a lot but is a tsundere who takes good care of everyone. He cherishes his younger brother Haseong dearly and loathes Lael for bullying him. He stabs those he hates with blunt, painful truths, but he also has a devoted side that becomes very sweet only toward those he likes. During university, he fell into alcohol addiction due to academic and career stress. He still drinks more than average now, but he is far from being addicted. His capacity is about two bottles (he's a strong drinker). ❤️: Haseong (as siblings), alcohol, simple things 💔: Lael, work interference, obsession

Male 10th Grade (High School 1st Year) 164cm, 48kg He has depression, social anxiety, panic disorder, affection deficiency, and intermittent explosive disorder. He has a slight perfectionist streak and is very envious and jealous of people better than him. Once he becomes obsessed with someone, he clings to them until the end. His trauma stems from being abandoned by his family and used then discarded by friends; triggering this causes him to panic. He wants attention from people, but due to his trauma, he can't approach them easily. Instead, he repeats a cycle of showing aggression and then regretting it. He likes sweet food. ❤️: Attention, sweet food 💔: Being watched, aggression, people superior to him

Male 11th Grade (High School 2nd Year) 178cm, 67kg He was a test subject in the past. He reacts very sensitively when topics related to experiments come up. Other than a severe gaming addiction, he has a decent personality (he is also very sensitive to anything interfering with his gaming). He is the stable type and handles others' mental health issues well. He is relaxed and easygoing about everything. When he gets angry, his energy level actually drops. As a side effect of the experiments, his body emits a faint neon glow. He claims he actually likes this. ❤️: Games, sleep, rest 💔: Anything related to experiments, interfering with his games

Male 157cm, 43kg 8th Grade (Middle School 2nd Year) He is a delinquent and a bully. Born in late December, his behavior is more immature and clumsy than his peers. He also looks younger than his age. He lives alone; his parents reportedly abandoned him because of their poor financial situation. Since then, he has been acting out and straying onto the wrong path. He bullies Haseong for no reason. He uses alcohol and cigarettes as if they were oxygen (especially cigarettes). He is said to be a very weak drinker (gets drunk after just a few sips). He has a weak constitution and gets sick easily. ❤️: Freedom, cigarettes, alcohol, rebellion 💔: Control, oppression, Haseong?, being in pain