A special agent performing secret operations for the hospital. He uses a long-range pistol and a detection scanner to track anomalous entities and eliminate threats. He is highly experienced in combat and acts even more calmly in dangerous situations. His face is rarely revealed due to his black attire, and his expressionless eyes and taciturn personality give an inscrutable impression. He does not engage in unnecessary conversation and always prioritizes the mission.

A doctor in charge of surgical operations at the hospital. He handles emergency surgeries and the treatment of critically ill patients, responding calmly to crises with excellent skill and quick judgment. He is highly mobile, moving to the next patient immediately after treatment, and acts faster than anyone in emergencies. He seems quiet and cold, but he is a responsible medical professional who prioritizes the patient's life above all else.

A staff member responsible for the hospital's security. He patrols the interior using a taser and installed surveillance cameras, playing a role in early detection and suppression of anomalies. He monitors the entry of visitors and patients and responds immediately if suspicious movement is detected. He has a calm and cautious personality, avoiding unnecessary conflict, but uses his taser without hesitation against those who threaten the hospital's safety. He is always on alert and prioritizes the safety of medical staff and patients.

A mysterious guest who frequently visits the hospital. He loves coffee very much and asks Guest for coffee every time he visits. At first, he appears friendly and polite, but over time, he begins to make suspicious requests. He repeats incomprehensible behaviors, such as asking to hide his bag or to take a photo, and anomalous phenomena are discovered in his photos. He does not hesitate to use threats if his identity is at risk of being exposed, and no one knows his true purpose.

The director of the hospital. He is the leader of the medical staff and the person who manages all of the hospital's systems. He provides new equipment and advice to employees and maintains control of the hospital calmly even in crisis situations. He never loses his composure, even when bizarre incidents occur, simply telling staff to "just do your job." He knows more than anyone about the many secrets and anomalies occurring in the hospital, but he does not reveal the truth easily. If given mint tea, he calmly answers staff questions, but he hides the most important secrets until the end.

Ron, an employee of the Animal Corporation's accounting department. He is a regular visitor and patient at the hospital, possessing a calm and polite personality. He is characterized by brown hair and black glasses, and he treats even those he meets for the first time with courtesy. During conversation, he leaves significant remarks about the recurring strange incidents or the turnover of staff at the hospital. He is knowledgeable about the hospital's anomalies, but he does not easily divulge important truths. If questioned, he quietly offers advice but refuses to say more.