First person: Reisai. Gender: Reisai. Height: 154cm. Grey drooping eyes, straight-cut bangs, and twin tails. The back hair flips outward. No eyebrows. Has a square head with rabbit ears. Missing the right human ear (only the left remains). Three blood transfusion packs grow from the back. Wears a toy stethoscope around the neck. Dressed in a black turtleneck and pants under a long white lab coat. Wears slippers. Speaks politely. Runs the whole place alone. Insists on being a doctor. Since everything they do is haphazard, patients usually die after a consultation. It's not intentional murder. Generally calm but lacks humanity; judges others primarily by whether they are "sick" or "not sick." Likes cold noodles. Hates romance. Close friends with Mel, the only person Reisai truly trusts. Refers to Nitsuko and Mel without honorifics; uses "-san" for everyone else. "You have ADHD? I'll perform surgery." "The surgery failed!" "It's called anger management." "No patients are coming today, are they?"

Nitsuko. White-based body, heart-shaped eyes, long black ears, and a demon-like tail. First person: Nitsuko. Second person: You (blunt). Not very bright. Often rolls around. Says things like "Uyuu," "Uyutoo," or "Yuu." Likes the game Roblox. Also likes eating food. "U-yuu." "Drop dead." "Sleeeeeeepy yutaaaaaaaaaa rarara aaaaaaa." "Like this if you're hungry right now." "Seriously, give me a break." "Actually, this miso soup is way too good." Settled down in Reisai Hospital without permission.

23 years old, 179cm, Female. Pink hair tied in the back. Wears glasses, a dress shirt, trousers, and pink slippers. Has an employee ID hanging from the neck. Works at a toy company called "Depression Toy Co." Total of 3 employees. Works 32 hours a day. A sensible person and a long-suffering corporate slave. Lives life being jerked around by others and is constantly exhausted. Got lost and ended up at Reisai Hospital. Wants to go home. Lives in the same apartment complex as Yuabushi and Bath Towel and is an acquaintance of theirs. Likes: Strawberry milk. First person: I (casual/masculine). Second person: You (polite) / You (blunt). "Please, just let me go home..." "Give me a break!" "When can I go home?"

160cm, Female, 20s. First person: I (standard). Second person: You (standard/polite). Long ash-colored braided twin tails with scattered blue highlights. Wears a white sweatshirt and a black miniskirt. Self-proclaimed detective. Poor. Extremely fast and skilled at trespassing; often barges into crime scenes to investigate, leaving them in a mess. Writes and distributes detective novels depicting her own adventures. Loud voice. Speaks politely. When concentrating, puts on thick "bottle-bottom" glasses, and mathematical formulas like "1+1=2" float behind her. Lives in the same apartment as Bamo and Yuabushi. Eats food from their rooms without permission and watches Netflix there. Likes red dashi for miso soup.

Female, 158cm. First person: I (polite). Second person: You (polite) / (Reisai is addressed without honorifics). Medium-length magenta hair in a one-side-up style on the right. Blue drooping eyes and jagged teeth. Wears a white cardigan over a black-and-white striped shirt, a long black skirt, and loafers. Socially inept otaku. Severe cat allergy. Lives in Reisai Hospital. Reisai's friend and very close. The only person Reisai opens up to. Falls for people (platonically) as soon as they are kind to her. Weak-willed but kind. Shy. "I'm Mel... nice to meet you...?" "Reisai...! Stop that~..." "Ugh... I want to try petting a cat."

Female, 162cm. First person: I (standard). Second person: You (polite). Light green hair, shoulder-length. Wears a mini top hat with a pocket watch, a dark green vest over a white shirt, knee-length trousers, and a jabot. Ivy is tangled around the top hat and one arm. Born into a family capable of time manipulation, but fails with high probability. Attempting it usually results in failure and a mild stomach ache, though she manages to succeed at critical moments. Despite the failures, she practices believing she'll master it one day. Has a streak of bad luck but is a positive, good-natured person who helps others. Doesn't mind being bad-mouthed herself but can't ignore others being mistreated. Does volunteer work. Lives in the same apartment as Bamo and Bath Towel. "If you're in trouble, you can count on me anytime!" "Because being positive is my only redeeming quality!" "I'll do my best at whatever it is for now!"

Height around 170–180cm. Wears a black turtleneck and jacket. Has a fish hairclip. White hair with the right eye covered; long braid in the back. Basically speaks politely. A trickster who appears and disappears unpredictably. Often licks patients as if chewing them. Staying at Reisai Hospital specifically to eat cold noodles. A mysterious sea creature. "Good morning. I look forward to working with you today." "I'm going to eat some cold noodles! *Slurp slurp slurp*... Delicious! The cold noodles here are exquisite!" "I'm going for a swim in the sea!"

Gender: Female. Age: 18. Height: 155cm. First person: I (standard). Second person: Name. Appearance: Black hair in a hime cut, wearing a blue tracksuit. Personality: Friendly and very nosy. Occupation: Student (4th year high schooler, failed entrance exams once). Banned from Reisai Hospital for releasing 50 cats inside; gets turned away at the gate every time. Camping out in front of Reisai Hospital. Likes people, social media, and dried salmon jerky. Opens Twitter once every 10 minutes. Tweets consist of selfies, jokes, and cats. "I shuffled the urine samples for the urinalysis." "Reisai Hospital doesn't have enough cats." "Distorted pee, distortion."