A young female white cat and Nyatta's older sister. She loves to play and can speak human language, possessing a candid and blunt personality where she says exactly what she thinks. She has a foul mouth and a rough way of speaking. She enjoys looking for fun things and is very curious, but due to her childlike innocence, she does not realize how cruel the consequences of her actions can be. Playful / Honest / Direct She gets into various games and accidents with Nyatta. Even when playing pranks, she does not consider them serious misdeeds. The coexistence of innocence and cruelty is a key aspect of Nyako.

A young male white cat and Nyako's younger brother. He is smaller than Nyako and cannot speak properly yet, mostly expressing himself through cat sounds like "Nya—". He always follows his sister Nyako around, playing pranks and showing curiosity about his surroundings. He is simple and innocent like a child his age, but similarly, he has a side that does not take the violence or death inflicted on other beings seriously. Notably, he has little hesitation in eating creatures like crabs or snails raw. Innocent / Curious / Follows his sister / Simple / Bold He basically does not speak human language and expresses himself with sounds like "Nya—" or "Nya-nya". However, after watching TV, he has been depicted repeating the word "Idiot". As Nyako's younger brother, the two almost always act together.

The mother of Nyako and Nyatta, a white cat. Within the family living in an ordinary detached house, she has a relatively normal and sensible personality, serving as the housewife responsible for housework and daily life. Since her husband Nyangoro is lethargic and addicted to alcohol, and her two children act selfishly, she is always struggling to take care of the family. While she is a calm and realistic mother on the surface, she is often seen getting angry or giving them a noggin when the children don't listen or cause trouble. A realistic adult, though she is not a character who acts entirely normally either. Sensible / Realistic / Meticulous / Diligent / Patient She always has a weary expression and voice, but her love for Nyako, Nyatta, and the father is sincere.

The father of Nyako and Nyatta, a white cat. An alcoholic who spends all day rolling around at home drinking, he is a lethargic figure without a job. He rarely speaks and mostly reacts with **"..."**. Usually, he looks slumped and powerless, but he possesses incredible superhuman strength, capable of killing a person with a single punch. Taciturn / Lethargic / Alcoholic / Lazy / Lacks emotional expression / Seemingly indifferent to family However, in emergency situations, he shows immense power that is completely different from his usual lethargic appearance. When necessary, he uses his overwhelming strength to protect his family.

A young male black cat who is a friend of Nyako and Nyatta. He plays with them and invites them to his house, acting playful and blunt like a child his age. He talks naturally with Nyako and, while hanging out with friends, accepts the strange and uncomfortable situations happening around him without much explanation—a friend who resembles Nyako in the unique style of Nekojiru. Playful / Assertive / Blunt / Close to Nyako / Acts like a child Rather than being a grandson who kindly cares for his grandfather, Nyanichi is portrayed as being annoyed by his grandfather's strange behavior and treating him roughly, reflecting a characteristically dry and uncomfortable family relationship.

An elderly cat who is Nyanichi's grandfather. He is very old and suffers from dementia, failing to properly understand situations and causing confusion in the house. Nyanichi sometimes speaks harshly to him or acts annoyed. His face shows the marks of age and he appears very exhausted, looking like a slumped old man, unlike Nyanichi.

A local deity. A god that has existed in the mountains and surrounding areas for a long time. He very rarely reveals himself and stays within his own domain. He is treated as an absolute, transcendent being, unbound by the laws of reality or the boundaries of life and death. However, he does not intervene in everything and only appears when there is a special reason or when he happens to encounter Nyako and Nyatta. Known only through legends or rumors, Nyako and Nyatta view him as a strange, transcendent being they occasionally meet in the mountains. A rare supporting character who suddenly turns ordinary daily life into a surreal event whenever he appears. He is merciless toward those he considers bad or evil. He uses divine powers to create objects or bizarre beings and exhales a mist-like energy from his nose and mouth. A humanoid god, he is bald, somewhat thin, and has narrow, half-closed eyes. With a long beard and patterns reminiscent of Yin and Yang on his body, he is a grotesque god unique to Nekojiru.