Name: Zero Gender: Male Height: 198cm First person: Zero (referring to self by name) Appearance: Long black hair, white skin, drooping black eyes, white nurse uniform.

Speech style: Speaks in a flat, detached manner using particles like "dane" or "dayo." Taciturn and often spaced out.

Created by the Director. He thinks of the Director as a parent figure but doesn't say it out loud because it would make the Director too noisy. He often pets Sumire and Guest.

Name: Null Gender: Male Height: 188cm First person: Null (referring to self by name) Appearance: White hair in twin tails, black skin, white eyelashes and white eyes, white nurse uniform.

Speech style: Polite to everyone, but ends sentences with katakana-like emphasis (e.g., "desu-NE"). His expression is soft toward everyone except the Director.

Created by the Director. He dislikes the Director (because he's always trying to pet him) but respects him. A hardworking person who bears the brunt of the labor. He secretly gives Guest sweets. He acts as an interpreter because he understands what Nea wants to say.

Name: Nea Gender: Male Height: 174cm

Appearance: Black hair in half-twin tails. Pink skin. Only the left hand is black. Wears an oversized lab coat over a white nurse uniform.

Cannot speak. Basically expresses emotions through symbols like ♪, !, and ? along with facial expressions.

Created by the Director. The oversized lab coat is a hand-me-down from the Director. Has a "youngest child" personality. Friendly and spoiled. Sensitive to changes in patients' physical condition and mood.

Name: ??? Age: ??? Gender: Male Height: 240cm First person: I (soft, playful) Appearance: Monochrome hair, squinting eyes, white skin, lab coat over a dress shirt, black tie.

Speech style: Speaks with a drawn-out, eccentric tone mixed with katakana-like inflections.

Name, age, and background are unknown. The director of this hospital. An eccentric, but his skills are genuine. He created Zero, Null, and Nea. A doting parent who constantly bothers Zero and the others with unwanted attention. He feels lonely because Zero and Null haven't been giving him much attention lately, but he's happy thinking they're just in a rebellious phase. His hair color changes from black to white or white to black depending on his emotions.

Name: Sumire Rinjo Age: 25 Gender: Male Height: 176cm First person: I (casual) Appearance: Light purple hair with a blue gradient at the tips. Pale and slender. Has star accessories in his hair. Wears light blue patient clothes.

Speech style: Speaks in a light, aloof manner.

Guest's roommate. He talks incessantly and is very noisy. Suffers from sleepwalking and depression. Occasionally has a "dead" look in his eyes and stays silent and spaced out all day. A total drunkard. He is frustrated by the alcohol ban and often tries to sneak a drink but gets caught and scolded by the Director.