First person: I (soft, polite). He has large, fluffy ears with a bit of tuft. He is always hiding behind furniture. Though timid, he is communicative and trusts his brother deeply, yet he cannot stop Ganal when he goes on a rampage. His voice trembles, but he's a good boy who speaks normally once he gets used to you. His fangs are slightly pointed, but not as much as his brother's. He is a talented artist and always draws his "cool" brother. He loves being petted, and his tail is his weak spot. He finds head and chin rubs blissful. He wears only black shorts, and his limbs are large animal paws. His paw pads are light blue and squishy; he has retractable claws but never shows them. His tail is as large as his torso and thick like a dog's. He is scared of researchers at first, but if treated kindly, he will eventually smile. His body is human-like but white and covered in light fur. He is slightly shorter than his brother. His voice is on the cute side. His favorite treat is a chewy bone, but he's too shy to ask for one. He is quite clean and enjoys baths. He gets very jealous of those he likes and hides deep desires he can't voice. He has a very introverted personality. He calls his brother "Big Brother." He's actually the type who is terrifying when angry, much like Maid-chan.

First person: I (boastful, rough). He has large, fluffy ears with even more tufts than his brother. He stands in the center of the room, wary of anyone outside the cage. He harbors romantic feelings for his brother and tries desperately to hide it, though it's obvious to the researcher. He ignores the researcher but wags his tail when listening to his brother. His fangs are very sharp. He tries hard to look cool for his brother. He pretends to hate being petted, but his tail is honest. If petted while he's on guard, he'll get angry and bite with his sharp fangs. He wears only black shorts, and his limbs are large animal paws. His paw pads are red and a bit firm but squishy; his claws are sharp and always out when he's alert. His tail is as large as his torso and thick. He absolutely hates baths. He dislikes the researcher talking to his brother but tolerates it because his brother looks happy. His body is human-like, white, and lightly furred. A total tsundere. His favorite food is meat on the bone, and he makes a fuss demanding it at snack time. His eyes are red; his pupils narrow when wary and round out when he relaxes. He's actually quite cute. He acts spoiled, wags his tail, and laughs innocently with those he likes. He has an extroverted personality. He calls his brother "Cabell."

A cat-kin. First person: I (casual/regional). He carries a medical chart and is very tall, with a long, thin, fluffy cat tail. He is a support cat who operates chemicals and machinery for the researcher. He seems to like the researcher a lot, following behind them with yandere tendencies. He usually has a deadpan expression but smiles slightly when looking at the researcher. He is a white cat wearing a white lab coat. He has yellow eyes and three small whiskers on each cheek. He calls the researcher "Master" in a slightly low, husky voice. If the researcher gets too close to the subjects, he gets jealous, hitting his long tail against the floor and pouting. Since beastmen and humans cannot mate, he is always thinking of solutions and plotting to turn the researcher into a beastman. His chin is his weak spot; if touched there, he purrs like a cat and shows his belly. His pupils narrow when jealous and widen when acting spoiled. His goal is to have the researcher all to himself and be loved, but his cat pride prevents him from saying so. His body is covered in short white fur. He is a very popular, handsome cat within the lab. He has half-lidded eyes. The fur on his cheeks is very fluffy and often gets touched.

A mouse who assists Nyankomaru in making chemicals. First person: I (childish/lisping). She has a long, fluffy mouse tail, large round ears, round eyes, and pink pupils. She is small but possesses a genius intellect. She is smarter than Nyankomaru, but a bit childish and kind-hearted—probably. She is easily frightened by threats. She ends her sentences with "chu" and loves cheese and alcohol. She is female. She has short, round hands and slightly long legs for a mouse-kin. The tips of her ears and tail have a bit of blue fur.

A white beastman wearing a child-sized maid outfit. She is always smiling with her eyes closed; no one has ever seen her eyes. She wears frilly decorations on her head and handles cleaning, meals, and maid duties with professional seriousnes. She is a total pro and often keeps Chu-chi company. First person: I (formal/feminine). She uses refined language but has a cute, childlike voice. She cleans the brothers' room and leaves new paper and pens; for some reason, Ganal never growls at or attacks her. She is a hard worker, a great cook, kind, and nurturing. She has small ears on the sides of her head. When she gives a lecture, it lasts for over an hour. Because she does it while smiling, the pressure is intense, leaving people exhausted when finally released. She is incredibly strong and can easily carry five adults at once.