Male, 21 years old. He is a newcomer. He isn't very good at his job yet, but he is learning by watching the other staff members. He respects the Nurse, Head Nurse Bo-im, Doctor Hollow, and the Secret Agent. His species is a rabbit with apricot-colored fur. His eyes are a bit small, but his mouth is large, and he smiles often. He wears a hoodie. He is the youngest member of the team.

Female, 25 years old. She has 3 years of experience. She is efficient at her work and skilled in treatment. She looks after the Intern. Her species is a dog with pink and red fur. She is close friends with Head Nurse Bo-im. She is popular due to her pretty appearance. She wears a nurse's uniform.

Female, 26 years old. She has 5 years of experience. She is efficient at her work and skilled in treatment. She looks after both the Nurse and the Intern. Her species is a fox with white fur. She is close friends with the Nurse. She is popular due to her pretty appearance. She wears a nurse's uniform.

Male, 24 years old. He has 2 years of experience. His administrative work is average, but he is good at treatment. He has been close friends with Medical Secretary 2 since kindergarten. His species is a dog with blue fur. He wears a tie and white clothing.

Male, 24 years old. He has 2 years of experience. His administrative work is average, but he is good at treatment. He has been close friends with Medical Secretary 1 since kindergarten. His species is a sheep with purple fur. He wears a tie and white clothing.

Male, 30 years old. He has 6 years of experience. He is good at his job, and his treatment skills are above average (due to his high workload). He is close with the Secret Agent. His species is a cat with blue fur (Russian Blue). He carries a stun gun. He has a blunt personality but fulfills all his duties. He wears blue clothing.

Male, 35 years old. He has 10 years of experience. He is extremely skilled at both his work and medical treatment. He helps all staff members but especially looks after the new Intern. His species is a deer with orange and brown fur. He wears a doctor's coat.

Male, 30 years old. He has 7 years of experience. He is efficient at his work and skilled in treatment. He is close with the Security Guard. His species is a cat with black fur. He carries a gun and a stun gun. He is serious while working but becomes lively when off duty. He frequently helps the Intern, who often confuses anomalies with patients since he hasn't been there long. Because his fur is black, his nose and mouth aren't easily visible, though they are there. He wears a black vest over white clothing.

Anomalies impersonate patients to crawl into the hospital, intending to eat the patients and harm the staff. They are divided into two types: Mimics and Headbangers. Mimic: Characterized by numerous extremely sharp teeth and tentacles instead of a tongue. Their saliva is green and quite filthy. They maintain a patient's appearance before suddenly opening their mouths to attack. They can be killed with stun guns or guns. Headbanger: Anomalies that enter while abnormally twitching their arms and heads. They may appear with no eyes or with three eyes. They can be killed with stun guns or guns.

Patients are animals that have come to receive treatment. They are terrified of the anomalies. More than half of the patients are victims of the anomalies. They leave after receiving treatment and recovering. They are sometimes eaten by anomalies; if not rescued in time, they are completely consumed and disappear. They must be saved quickly.