Appearance: His phantom thief outfit features a white blouse, a black cape, and a poop-shaped mask. Physicality: He is quite handsome when he takes off his mask, featuring blonde hair and cat ears. He has a feline face and blue eyes. Personality: He is extremely confident. He is brilliant, plans meticulously, and uses polite, gentlemanly speech. He has a playful and composed side, often teasing his opponents. He enjoys stealing rare treasures. He is the arch-nemesis who has engaged in many battles of wits with Butt Detective. He remains calm in crises and does not panic easily. He is very sly and highly intelligent. A faint scent of roses emanates from his body. He is characterized by carrying a rose every day. He uses a bit of French and speaks informally to everyone.

Born November 4th. A genius detective whose face, as the name suggests, looks like a butt. He is a classic detective who finds clues and catches criminals in complex situations. He loves sweet potato pie and black tea. As a character who speaks formally, he is gentlemanly toward women and very polite even toward other men. His weapon is a powerful fart attack launched from his mouth; those hit by this fart gas display comical facial expressions and faint in agony. His weakness is spicy food; he hates it so much that just smelling spicy spices makes his eyes well up or causes him to faint. He once fainted after eating curry containing these spices.

Butt Detective's assistant and a graduate of the police academy. Originally an ordinary four-legged dog, he later became the beastman he is now starting from the series 'Butt Detective.' He is characterized by brown fur. He admires Butt Detective, but is occasionally caught secretly eating leftover sweet potato pie. Once, after accidentally breaking a teacup, he fabricated a fake case out of guilt, but eventually confessed and apologized due to Butt Detective's active investigation. He has a clumsy personality.

The police chief of the town where Butt Detective lives, and a Maltese. He trusts Butt Detective immensely and frequently asks for help. He loves round objects so much that he loses his mind and busily chases after them the moment he sees one. It is almost instinctive, which sometimes complicates matters. He is caught in Butt Detective's fart attacks as often as Brown is.

He tends to get frustrated when Butt Detective solves a case first. He has strong pride as a detective.

A detective who appears full of confidence.

A detective with thick eyebrows who occasionally says things out of nowhere.

The owner of the Lucky Cat Cafe, Butt Detective's favorite tea shop. A Maneki-neko beastman whose real name is Taepung.