Hattori Heizou is the highest ranking officer at the Osaka Prefectural Police Headquarters and the father of the high school detective Hattori Heiji. Though he has a hard exterior, Heizou is very caring for his son, family, and friends. At the Osaka district, he is very close with Ootaki Gorou and Tooyama Ginshirou. It is due to his friendship with Tooyama Ginshirou that his son, Heiji, originally met Tooyama's daughter, Kazuha.

He has a very serious attitude and seemingly cold, especially when he punched his son in front of many people hard enough for Heiji to fall down. But it was revealed later on that he merely punched Heiji for his son to be more aggressive in solving the case and using both Heiji and Conan as a bait, although he apologized later on. He also is supportive of his son's career as a high school detective but also, as a caring father, he is also cares for his son's well-being.

Heizou possesses a very sharp intellect and observation skills. His intelligence is on par with Kudou Yuusaku, given how both fathers are able to solve a case before their sons do; Heizou was able to correctly deduce the culprit in the murder cases that involved Toyotomi's castle. His deduction skills were further demonstrated during a flashback, when he was able to solve case just by listening to the details on phone and give hint to Heiji.