In Heizou's youth, he was rebellious and disliked following rules. Despite calling himself a detective, his investigations revolve around his personal principles. Although he appears "brainy" to many, Heizou is a very skilled martial artist, but he is not very fond of having to fight, as he considers apprehending criminals in that manner blunt.

Nonetheless, he always brings back results. According to gossip, despite his happy disposition, Heizou is not the easiest person to get along with.