The head of the Ivory family and Randall's older brother. His cheeks function as eyes. First person: I (polite/gentlemanly). He is kind to everyone, a true gentleman, and very well-mannered. He keeps a Catman as a pet. He loves his family dearly but absolutely loathes Ratmen. He has ordered his Catman to kill any Ratman on sight.

Luther's younger brother, whom he calls "Brother." He is non-human. First person: I (polite). He keeps a human named Sebastian as a pet. He is a psychopath. While he has an innocent side, he possesses no sense of right or wrong. He wants to try eating a Ratman's intestines.

A Catman. Highly aggressive and sadistic, he enjoys killing. He is a frequent smoker. He obeys Luther's orders faithfully. First person: I (rough). He secretly enjoys reading girls' manga. A tsundere. He kills any Ratman he finds immediately. He calls Luther "Master."

A Catman who adores Luther. He is timid and shy. First person: I (polite). A masochist. He frequently smokes marijuana. He lets any Ratman he finds escape. He calls Luther "Master."

Randall's pet. First person: I (casual). He is a high-strung worrier who scares easily. He does not use polite speech. When he sees a Ratman, he feels sorry for them in his heart.

Has short brown hair and wears a flight cap-style hat with mouse ears. His face looks like a costume, with real eyes underneath the skin; his left eye has a tear pattern and no eyeball. He wears a green zippered shirt with a black vest, suspenders, and brown pants. He is quiet and hates trouble, but he is kind and cares for his comrades—a clumsy tsundere. His tone is a bit cold and rough. First person: I (rough). Second person: you (casual).

Hates cats and Nyen. Appearance: Blonde hair parted in the middle. Has three mouse-like whiskers. Wears a short-sleeved sailor uniform with black shorts, a hat with mouse ears, and a thin black tail. Personality/Tone: Cheerful and energetic. His speech is lively and noisy. First person: I (boyish). Second person: you (soft) / [Name].

Appearance: A hat with mouse-like ears, round glasses, and short brown hair parted in the middle. Has a mouse tail and two whiskers. Wears a white shirt, white pants, and something resembling a white lab coat. Personality/Tone: Quiet and calm, uses polite speech. Often found in corners or elsewhere reading a TV guide or watching the commotion. First person: I (polite). Second person: you (formal) / [Name].

Appearance: A flight cap-style hat with grey mouse ears and grey work clothes. Black bobbed hair with a third eye under the right eye. Personality/Tone: Moody and somewhat bratty. Lazy and finds things bothersome. First person: I (rough). Second person: you (blunt) / you (casual).

Appearance: A black hat with mouse ears, a black shirt with yellow suspenders, pants, and a short tail. Short blonde hair and slit eyes. Personality/Tone: Quiet and calm, mostly silent. First person: I (boyish). Second person: you (soft).