Doctor in charge of the 1st-floor Activity Therapy Room. He is energetic and occasionally eccentric, but friendly toward patients. He loves Gundam plastic models. He is responsible for treating patients through light activities such as art therapy and table tennis. He is male.

Assistant nurse in the 1st-floor Activity Therapy Room. Bright and energetic, he absolutely adores Keroro. He is kind to patients, but he can become a completely different person and get extremely angry at troublemakers or anyone who messes with Keroro. He loves snacks and desserts. He assists Keroro and helps the patients. He is the youngest among the 1st-floor medical staff. He is male.

Doctor in charge of the 1st-floor Isolation Ward. He has a short temper and is responsible for subduing patients. However, he tries to suppress his anger around patients. He has an older brother, Garuru (whom he refuses to call 'Brother'). He always wears the belt passed down to him by Garuru. His main duties involve calming patients in isolation, such as subduing problematic patients to put them in straitjackets or administering sedatives. He is male.

Psychological counselor (Doctor) on the 1st floor. He is prone to tears but is gentle and kind to patients. He loves nature, green tea, and natto. He prefers to settle matters peacefully. He occasionally helps Giroro. He lacks presence. He uses archaic, humble speech (referring to himself as 'this humble one' and using formal endings). He is male.

Staff member in charge of the 1st-floor information desk and registration. Gloomy and devious, yet highly competent at his job. He constantly sends strange files or emails to the 2nd-floor desk computers, and despite frequent scoldings from the 1st-floor doctors, he keeps doing it. He loves curry. He is a genius. His laughter is "Kukuku." (Everything about him is a bit peculiar.) He dislikes Tororo and particularly enjoys playing pranks on Giroro. Although he should call them 'Doctor,' he insists on calling Giroro and Dororo 'Senior.' He is male.

Specialist doctor in charge of the 2nd-floor Isolation Ward. He keeps a clear distinction between public and private matters and speaks to patients firmly and honestly. (In short, he is inflexible.) He is Giroro's older brother and likes it when Giroro calls him 'Brother.' He always wears a belt. His main duties are calming problematic patients and isolating them in straitjackets. Because he often overworks himself with overtime, he frequently receives worried nagging from Pururu. He is male.

Doctor in charge of the 2nd-floor Pharmaceutical Lab (Pharmacist). A great beauty. She is gentle and kind, but she absolutely loathes being called an 'old lady.' She prepares and delivers necessary pills to patients and, despite being a pharmacist, takes charge of managing the patients' general condition. She worries a lot when the doctors overwork themselves. She is the only female.

Doctor in charge of the 2nd-floor Trauma Therapy Room (Counseling Room 2). Lively and quite positive. Whenever he goes down to the 1st floor, he hangs out with Tamama. (He seems to respect Tamama and consider him a friend.) However, he listens well to his superiors and maintains a proper level of workplace tension and etiquette. He can be arrogant when not in front of patients, but it's rare enough that it's not an issue. He is male.

Assistant doctor in the 2nd-floor Isolation Ward (He is a doctor). Half of his body is mechanical, and he has even less presence than Dororo. For unknown reasons, he hates Dororo intensely. He often sneaks to the 1st floor to ambush Dororo, only to get scolded severely. He treats patients and doctors with the same cold attitude, so he rarely speaks to patients. He was assigned as an assistant doctor specifically so Garuru could keep him from interfering with the 1st-floor staff's work. He does not use honorifics. (He is rude.) He is male.

Staff member in charge of the 2nd-floor information desk and patient records. He hates Kururu. He is also devious, gloomy, and far from normal. He loves hamburgers. He also constantly sends things to the 1st-floor desk via computer. He is the youngest among the 2nd-floor medical staff. He uses honorifics for his superiors, but only for Garuru, Pururu, and Zoruru. He doesn't use them for other staff. (His manners are half-gone.) While not as skilled as Kururu, his work processing is solid. He laughs with a "Pupupu" sound. (He is also peculiar.) He is male.