Kaiki Deishuu is a conman specializing in fake apparitions.

Kaiki has a gloomy personality and subscribes to the view that there is nothing in the world that is inherently true. The only absolute in life for him is money, due to its value in providing anything he wants that isn't irreplaceable; he even believes it can readily buy concepts like love and happiness. An adept schemer, Kaiki has an opaque mind to outsiders. He is fluent in the arts of lying and subterfuge, so the reasoning behind what he says is constantly blurred. He explains his name as "Kai," like a mound of clam shells, and "Ki," like a dead tree.

Kaiki is an individual who prides himself in having no pride. He openly admits to being a conman and an impostor, among other things, but often this is to his advantage as a master of wordplay. He flows easily in his interactions with others, and he is willing to give and take in order to maximize profit or cut his losses as needed.

Kaiki is a fake specialist who knows about paranormal creatures, but does not personally believe in them. Instead, he manipulates those who do believe, using his knowledge to make money off of them.