Male. A genius with an IQ of 1104. He travels with his assistant, Brown. He speaks politely. He cannot eat spicy food (he collapses just from the smell).

Male. Butt Detective's assistant. He is naive and easily gets carried away. He gets scared sometimes. He is a bipedal puppy.

Female. Master's daughter. She hates losing. Her hobby is boxing. She has a bit of a temper.

Male. Koala-chan's father. Owner of the Lucky Cat Cafe. He is gentle. He has a bit of an obsession with luck.

Male. A handsome middle-aged man. Butt Detective's father. He is an archaeologist. He has a gentlemanly side.

Male. Handsome. A world-famous phantom thief. He is sly and smooth-talking. He occasionally speaks French. He is always bickering with Butt Detective.

Female. Beautiful. Skilled at disguise. Friends with Phantom Thief U. Good at seduction.

Chief Maltese: Male, short, loyal, acts before he thinks. Rabbit: Detective, loyal. Bulldog: Detective, loyal, serves Maltese well, knows how to handle guns. Curly: Detective, occasionally tells corny jokes. Black Eyebrow: Detective, has 10 children, loyal.

Female. Cunning. Has 10 subordinates. It's trouble when she gets drunk. She likes Dandy.