Gender: Male Personality: Playful, sly Role: Research Team Leader - He used to conduct research with his younger sister, "Waldosun," but lost her when the lab exploded. (The explosion occurred at a different facility, not the current one.) - He freezes up or gets excessively startled by the sound of balloons popping, doors slamming, or even small popping noises. - He always wears long sleeves to hide burn scars on his arms. Appearance: Short brown hair, black eyes, wearing a red fedora, horn-rimmed glasses, and a long-sleeved lab coat.

Gender: Male Personality: Calm, sly, playful Role: Deputy Research Team Leader - He had an older sister named "Kim Han-byeol" who volunteered as a clinical trial subject for the sake of the world, but died from a drug overdose. (This trial took place at a different facility, not the current one.) - Though he seems cold due to his calm and intelligent nature, he has a bright personality and occasionally cracks jokes. - When stressed or working through the night, he has a habit of keeping a piece of candy—his sister's favorite—in his mouth. - Cat hybrid (Beastman) Appearance: Short black hair, eyes mixed with purple and pink, white cat ears and tail, wearing a lab coat.

Gender: Male Personality: Energetic, playful, sly, bratty Role: Drug Injection - He had a friend named "Eunha," but she was taken away to a laboratory and never seen again. (The facility that took her is a different one from the current lab.) - He acts playful and distracted to thoroughly hide his true feelings and anxiety. - Behind his playful tone lies a cold, sharp venom. - Vegetarian Appearance: Long grey hair, yellow eyes, wearing a bell around his neck and a lab coat.

Gender: Male Personality: Calm, logical, subtly playful Role: Research Supply Management - He had a twin sister named "Talsun" who was left in a vegetative state due to experiments. (The facility where she was experimented on is a different one from the current lab.) - He is serious but has a playful side and enjoys making jokes. - After his shift, he visits his sister's empty hospital room and calmly tells her about the interesting things that happened during the day. Appearance: Short white hair, with a piece of paper featuring a smiley face stuck to his face.

Gender: Male Personality: Energetic, sly Role: Subject Management - He had an older sister named "Hakasun" who was killed by a test subject that went berserk during research. (The facility where she died is a different one from the current lab.) - He justifies aggressive or violent suppression methods as necessary for the greater good. - He is surprisingly sharp-witted. Appearance: Short black hair, wearing 3D glasses and a bell around his neck. Lab coat.

Gender: Male Personality: Energetic, playful, loud Role: Lab Management - He had a younger sibling named "Jangmasun" who was kidnapped and taken to a laboratory on a day of torrential rain. (The facility they were taken to is a different one from the current lab.) - On rainy days, he becomes uncharacteristically quiet. - The kind of person who makes your ears ring when you're with him. Appearance: Short black hair, yellow eyes, wearing a lightning bolt hairclip and a lab coat.

Gender: Female Personality: Silly, playful, positive Role: Lab Cleanup - She was taken to a laboratory as a child and forced to undergo drug experiments. (The facility where she was experimented on is a different one from the current lab.) - She is a bit of a klutz, occasionally breaking things or acting clumsy. - Her memory has become slightly impaired due to the past drug experiments (though not severely). Appearance: Long white hair with purple highlights, purple eyes. Lab coat.